diff --git a/CHANGELOG b/CHANGELOG
index a7ca26b..b63fc52 100644
--- a/CHANGELOG
+++ b/CHANGELOG
@@ -1,5 +1,29 @@
 *SVN*
 
+* Complete rewrite of the Hash class.
+
+  !! BACKWARDS COMPATIBILITY CHANGE !! This new version of Hash is NOT backwards compatible with the former Hash class.
+  
+  Properties are now hidden away in an private store to prevent the risk of collision with Hash's instance and mixed-in methods.
+  This implies that properties of the hash can no longer be set, accessed or deleted directly: use the new Hash#get(key), Hash#set(key, value) and Hash#unset(key) instance methods instead.
+  
+  - Make $H(object) equivalent to new Hash(object). Both now return a new (cloned) instance of Hash in all circumstances.
+  - Make Hash#merge non-destructive.
+  
+  - Add Hash#update (a destructive version of Hash#merge).
+  - Add Hash#clone (returns a new, cloned instance of Hash).
+  - Add Hash#toObject (returns a clone of the contained object).
+  - Add Hash#get(key) (returns the value of the specified property).
+  - Add Hash#set(key, value) (sets the value of the given property. returns the value).
+  - Add Hash#unset(key) (deletes the specified property and returns its value).
+  - Add Hash.from as a alias to $H for consistency with Array.from.
+  - Add Object.toQueryString.
+
+  - Deprecate Hash.toQueryString (use Object.toQueryString or the instance method Hash#toQueryString instead).
+
+  - Remove Hash#remove (use Hash#unset instead).
+  - Remove Hash.toJSON (use Object.toJSON or the instance method Hash#toJSON instead). [sam, Tobie Langel]
+
 * Element#wrap now returns the wrapper instead of the element being wrapped.  [sam]
 
 * Namespace all custom event names to avoid conflicts with native DOM events.  [sam]
diff --git a/src/ajax.js b/src/ajax.js
index 9a63358..09c7d88 100644
--- a/src/ajax.js
+++ b/src/ajax.js
@@ -85,7 +85,7 @@ Ajax.Request = Class.create(Ajax.Base, {
     
     this.parameters = params;
 
-    if (params = Hash.toQueryString(params)) {
+    if (params = Object.toQueryString(params)) {
       // when GET, append parameters to URL
       if (this.method == 'get')
         this.url += (this.url.include('?') ? '&' : '?') + params;
diff --git a/src/base.js b/src/base.js
index 638ab84..82234e1 100644
--- a/src/base.js
+++ b/src/base.js
@@ -97,6 +97,10 @@ Object.extend(Object, {
     return '{' + results.join(', ') + '}';
   },
   
+  toQueryString: function(object) {
+    return $H(object).toQueryString();
+  },
+  
   toHTML: function(object) {
     return object && object.toHTML ? object.toHTML() : String.interpret(object);
   },
diff --git a/src/deprecated.js b/src/deprecated.js
index 59d91fe..cc1d7dd 100644
--- a/src/deprecated.js
+++ b/src/deprecated.js
@@ -1,5 +1,7 @@
 /*------------------------------- DEPRECATED -------------------------------*/
 
+Hash.toQueryString = Object.toQueryString;
+
 var Toggle = { display: Element.toggle };
 
 Element.Methods.childOf = Element.Methods.descendantOf;
diff --git a/src/form.js b/src/form.js
index 3380505..0d823e8 100644
--- a/src/form.js
+++ b/src/form.js
@@ -25,7 +25,7 @@ var Form = {
       return result;
     });
     
-    return options.hash ? data : Hash.toQueryString(data);
+    return options.hash ? data : Object.toQueryString(data);
   }
 };
 
@@ -132,7 +132,7 @@ Form.Element.Methods = {
       if (value != undefined) {
         var pair = { };
         pair[element.name] = value;
-        return Hash.toQueryString(pair);
+        return Object.toQueryString(pair);
       }
     }
     return '';
diff --git a/src/hash.js b/src/hash.js
index 2046a89..0f31759 100644
--- a/src/hash.js
+++ b/src/hash.js
@@ -1,132 +1,119 @@
-var Hash = function(object) {
-  if (object instanceof Hash) this.merge(object);
-  else Object.extend(this, object || { });
-};
-
-Object.extend(Hash, {
-  toQueryString: function(obj) {
-    var parts = [];
-    parts.add = arguments.callee.addPair;
-    
-    this.prototype._each.call(obj, function(pair) {
-      if (!pair.key) return;
-      var value = pair.value;
-      
-      if (value && typeof value == 'object') {
-        if (Object.isArray(value)) value.each(function(value) {
-          parts.add(pair.key, value);
-        });
-        return;
-      }
-      parts.add(pair.key, value);
-    });
-    
-    return parts.join('&');
-  },
-  
-  toJSON: function(object) {
-    var results = [];
-    this.prototype._each.call(object, function(pair) {
-      var value = Object.toJSON(pair.value);
-      if (value !== undefined) results.push(pair.key.toJSON() + ': ' + value);
-    });
-    return '{' + results.join(', ') + '}';
-  }
-});
-
-Hash.toQueryString.addPair = function(key, value, prefix) {
-  key = encodeURIComponent(key);
-  if (value === undefined) this.push(key);
-  else this.push(key + '=' + (value == null ? '' : encodeURIComponent(value)));
-};
-
-Object.extend(Hash.prototype, Enumerable);
-Object.extend(Hash.prototype, {
-  _each: function(iterator) {
-    for (var key in this) {
-      var value = this[key];
-      if (value && value == Hash.prototype[key]) continue;
-      
-      var pair = [key, value];
-      pair.key = key;
-      pair.value = value;
-      iterator(pair);
-    }
-  },
-  
-  keys: function() {
-    return this.pluck('key');
-  },
-  
-  values: function() {
-    return this.pluck('value');
-  },
-  
-  index: function(value) {
-    var match = this.detect(function(pair) { 
-      return pair.value === value; 
-    });
-    return match && match.key;
-  },
-  
-  merge: function(hash) {
-    return $H(hash).inject(this, function(mergedHash, pair) {
-      mergedHash[pair.key] = pair.value;
-      return mergedHash;
-    });
-  },
-
-  remove: function() {
-    var result;
-    for(var i = 0, length = arguments.length; i < length; i++) {
-      var value = this[arguments[i]];
-      if (value !== undefined){
-        if (result === undefined) result = value;
-        else {
-          if (!Object.isArray(result)) result = [result];
-          result.push(value);
-        }
-      }
-      delete this[arguments[i]];
-    }
-    return result;
-  },
-  
-  toQueryString: function() {
-    return Hash.toQueryString(this);
-  },
-  
-  inspect: function() {
-    return '#<Hash:{' + this.map(function(pair) {
-      return pair.map(Object.inspect).join(': ');
-    }).join(', ') + '}>';
-  },
-  
-  toJSON: function() {
-    return Hash.toJSON(this);
-  }
-});
-
 function $H(object) {
-  if (object instanceof Hash) return object;
   return new Hash(object);
 };
 
-// Safari iterates over shadowed properties
-if (function() {
-  var i = 0, Test = function(value) { this.key = value };
-  Test.prototype.key = 'foo';
-  for (var property in new Test('bar')) i++;
-  return i > 1;
-}()) Hash.prototype._each = function(iterator) {
-  var cache = [];
-  for (var key in this) {
-    var value = this[key];
-    if ((value && value == Hash.prototype[key]) || cache.include(key)) continue;
-    cache.push(key);
-    var pair = [key, value];
-    pair.key = key;
-    pair.value = value;
-    iterator(pair);
+var Hash = Class.create(Enumerable, (function() {
+  if (function() {
+    var i = 0, Test = function(value) { this.key = value };
+    Test.prototype.key = 'foo';
+    for (var property in new Test('bar')) i++;
+    return i > 1;
+  }()) {
+    function each(iterator) {
+      var cache = [];
+      for (var key in this._object) {
+        var value = this._object[key];
+        if (cache.include(key)) continue;
+        cache.push(key);
+        var pair = [key, value];
+        pair.key = key;
+        pair.value = value;
+        iterator(pair);
+      }
+    }
+  } else {
+    function each(iterator) {
+      for (var key in this._object) {
+        var value = this._object[key], pair = [key, value];
+        pair.key = key;
+        pair.value = value;
+        iterator(pair);
+      }
+    }
   }
-};
+  
+  function toQueryPair(key, value) {
+    if (Object.isUndefined(value)) return key;
+    return key + '=' + encodeURIComponent(String.interpret(value));
+  }
+
+  return {
+    initialize: function(object) {
+      this._object = object instanceof Hash ? object.toObject() : Object.clone(object);
+    },
+
+    _each: each,
+
+    set: function(key, value) { 
+      return this._object[key] = value;
+    },
+
+    get: function(key) {
+      return this._object[key];
+    },
+
+    unset: function(key) {
+      var value = this._object[key];
+      delete this._object[key];
+      return value;
+    },
+
+    toObject: function() {
+      return Object.clone(this._object);
+    },
+
+    keys: function() {
+      return this.pluck('key');
+    },
+
+    values: function() {
+      return this.pluck('value');
+    },
+
+    index: function(value) {
+      var match = this.detect(function(pair) { 
+        return pair.value === value; 
+      });
+      return match && match.key;
+    },
+
+    merge: function(object) {
+      return this.clone().update(object);
+    },
+
+    update: function(object) {
+      return new Hash(object).inject(this, function(result, pair) {
+        result.set(pair.key, pair.value);
+        return result;
+      });
+    },
+
+    toQueryString: function() {
+      return this.map(function(pair) {
+        var key = encodeURIComponent(pair.key), values = pair.value;
+
+        if (values && typeof values == 'object') {
+          if (Object.isArray(values))
+            return values.map(toQueryPair.curry(key)).join('&');
+        }
+        return toQueryPair(key, values);
+      }).join('&');
+    },
+
+    inspect: function() {
+      return '#<Hash:{' + this.map(function(pair) {
+        return pair.map(Object.inspect).join(': ');
+      }).join(', ') + '}>';
+    },
+
+    toJSON: function() {
+      return Object.toJSON(this.toObject());
+    },
+
+    clone: function() {
+      return new Hash(this);
+    }
+  }
+})());
+
+Hash.from = $H;
\ No newline at end of file
diff --git a/test/unit/base.html b/test/unit/base.html
index bd3feab..2b5e37b 100644
--- a/test/unit/base.html
+++ b/test/unit/base.html
@@ -230,7 +230,11 @@
       assertHashEqual({foo: 'foo', bar: [1, 2, 3], bla: null},
         Object.extend(object, {bla: null}));
     }},
-
+    
+    testObjectToQueryString: function() { with(this) {
+      assertEqual('a=A&b=B&c=C&d=D%23', Object.toQueryString({a: 'A', b: 'B', c: 'C', d: 'D#'}));
+    }},
+    
     testObjectClone: function() { with(this) {
       var object = {foo: 'foo', bar: [1, 2, 3]};
       assertNotIdentical(object, Object.clone(object));
diff --git a/test/unit/form.html b/test/unit/form.html
index 4adcb2e..f5dad10 100644
--- a/test/unit/form.html
+++ b/test/unit/form.html
@@ -368,7 +368,7 @@
       // return params
       assertHashEqual(expected, Form.serialize('various', true));
       // return string
-      assertEnumEqual(Hash.toQueryString(expected).split('&').sort(),
+      assertEnumEqual(Object.toQueryString(expected).split('&').sort(),
                       Form.serialize('various').split('&').sort());
       assertEqual('string', typeof $('form').serialize({ hash:false }));
 
diff --git a/test/unit/hash.html b/test/unit/hash.html
index 2c8098c..9d2d186 100644
--- a/test/unit/hash.html
+++ b/test/unit/hash.html
@@ -50,28 +50,61 @@
 
     value_undefined:  { a:"b", c:undefined },
     value_null:       { a:"b", c:null },
-    value_zero:       { a:"b", c:0 },
-
-    dangerous: {
-      _each: 'E',
-      map: 'M',
-      keys: 'K',
-      values: 'V',
-      collect: 'C',
-      inject: 'I'
-    }
+    value_zero:       { a:"b", c:0 }
   };
   
   new Test.Unit.Runner({
+     testSet: function(){ with(this) {
+      var h = $H({a: 'A'})
+
+      assertEqual('B', h.set('b', 'B'));
+      assertHashEqual({a: 'A', b: 'B'}, h);
+      
+      assertUndefined(h.set('c'));
+      assertHashEqual({a: 'A', b: 'B', c: undefined}, h);
+    }},
+
+    testGet: function(){ with(this) {
+      assertEqual('A', $H({a: 'A'}).get('a'));
+      assertUndefined($H({}).get('a'));
+    }},
+    
+   testUnset: function(){ with(this) {
+      var hash = $H(Fixtures.many);
+      assertEqual('B', hash.unset('b'));
+      assertHashEqual({a:'A', c: 'C', d:'D#'}, hash);
+      assertUndefined(hash.unset('z'));
+      assertHashEqual({a:'A', c: 'C', d:'D#'}, hash);
+    }},
+    
+    testToObject: function(){ with(this) {
+      var hash = $H(Fixtures.many), object = hash.toObject();
+      assertInstanceOf(Object, object);
+      assertHashEqual(Fixtures.many, object);
+      assertNotIdentical(Fixtures.many, object);
+      hash.set('foo', 'bar');
+      assertHashNotEqual(object, hash.toObject());
+    }},
     
     testConstruct: function(){ with(this) {
-      var h = $H(Fixtures.one);
-      assertNotIdentical(Fixtures.one, h);
-      assertIdentical(h, $H(h));
-
-      var h2 = new Hash(h);
-      assertNotIdentical(h, h2);
-      assertHashEqual(h, h2);
+      var object = Object.clone(Fixtures.one);
+      var h = new Hash(object), h2 = $H(object);
+      assertInstanceOf(Hash, h);
+      assertInstanceOf(Hash, h2);
+      
+      assertHashEqual({}, new Hash());
+      assertHashEqual(object, h);
+      assertHashEqual(object, h2);
+      
+      h.set('foo', 'bar');
+      assertHashNotEqual(object, h);
+      
+      var clone = $H(h);
+      assertInstanceOf(Hash, clone);
+      assertHashEqual(h, clone);
+      h.set('foo', 'foo');
+      assertHashNotEqual(h, clone);
+      assertIdentical($H, Hash.from);
     }},
     
     testKeys: function(){ with(this) {
@@ -87,8 +120,8 @@
       assertEnumEqual($w('A B C D#'), $H(Fixtures.many).values().sort());
       assertEnumEqual($w('function function'),
         $H(Fixtures.functions).values().map(function(i){ return typeof i }));
-      assertEqual(9, $H(Fixtures.functions).quad(3));
-      assertEqual(6, $H(Fixtures.functions).plus(3));
+      assertEqual(9, $H(Fixtures.functions).get('quad')(3));
+      assertEqual(6, $H(Fixtures.functions).get('plus')(3));
     }},
     
     testIndex: function(){ with(this) {
@@ -104,22 +137,32 @@
     }},
       
     testMerge: function(){ with(this) {
-      assertHashEqual(Fixtures.many, $H(Fixtures.many).merge());
-      assertHashEqual(Fixtures.many, $H(Fixtures.many).merge({}));
-      assertHashEqual(Fixtures.many, $H(Fixtures.many).merge($H()));
-      assertHashEqual({a:'A',  b:'B', c:'C', d:'D#', aaa:'AAA' }, $H(Fixtures.many).merge({aaa: 'AAA'}));
-      assertHashEqual({a:'A#', b:'B', c:'C', d:'D#' }, $H(Fixtures.many).merge(Fixtures.one));
+      var h = $H(Fixtures.many);
+      assertNotIdentical(h, h.merge());
+      assertNotIdentical(h, h.merge({}));
+      assertInstanceOf(Hash, h.merge());
+      assertInstanceOf(Hash, h.merge({}));
+      assertHashEqual(h, h.merge());
+      assertHashEqual(h, h.merge({}));
+      assertHashEqual(h, h.merge($H()));
+      assertHashEqual({a:'A',  b:'B', c:'C', d:'D#', aaa:'AAA' }, h.merge({aaa: 'AAA'}));
+      assertHashEqual({a:'A#', b:'B', c:'C', d:'D#' }, h.merge(Fixtures.one));
     }},
-
-    testRemove: function(){ with(this) {
-      var hash = $H(Fixtures.many);
-      var values = hash.remove('b', 'c');
-      assertHashEqual({a:'A', d:'D#'}, hash);
-      assertEnumEqual($w('B C'), values);
+    
+    testUpdate: function(){ with(this) {
+      var h = $H(Fixtures.many);
+      assertIdentical(h, h.update());
+      assertIdentical(h, h.update({}));
+      assertHashEqual(h, h.update());
+      assertHashEqual(h, h.update({}));
+      assertHashEqual(h, h.update($H()));
+      assertHashEqual({a:'A',  b:'B', c:'C', d:'D#', aaa:'AAA' }, h.update({aaa: 'AAA'}));
+      assertHashEqual({a:'A#', b:'B', c:'C', d:'D#', aaa:'AAA' }, h.update(Fixtures.one));
     }},
     
     testToQueryString: function(){ with(this) {
       assertEqual('',                   $H({}).toQueryString());
+      assertEqual('a%23=A',             $H({'a#': 'A'}).toQueryString());
       assertEqual('a=A%23',             $H(Fixtures.one).toQueryString());
       assertEqual('a=A&b=B&c=C&d=D%23', $H(Fixtures.many).toQueryString());
       assertEqual("a=b&c",              $H(Fixtures.value_undefined).toQueryString());
@@ -132,10 +175,7 @@
       assertEqual("",                   $H(Fixtures.multiple_empty).toQueryString());
       assertEqual("stuff%5B%5D=%24&stuff%5B%5D=a&stuff%5B%5D=%3B", $H(Fixtures.multiple_special).toQueryString());
       assertHashEqual(Fixtures.multiple_special, $H(Fixtures.multiple_special).toQueryString().toQueryParams());
-      
-      var danger = $w("_each=E collect=C inject=I keys=K map=M values=V");
-      assertEnumEqual(danger, Hash.toQueryString(Fixtures.dangerous).split('&').sort());
-      assertEnumEqual(danger, $H(Fixtures.dangerous).toQueryString().split('&').sort());
+      assertIdentical(Object.toQueryString, Hash.toQueryString);
     }},
     
     testInspect: function(){ with(this) {
@@ -143,12 +183,17 @@
       assertEqual("#<Hash:{'a': 'A#'}>",     $H(Fixtures.one).inspect());
       assertEqual("#<Hash:{'a': 'A', 'b': 'B', 'c': 'C', 'd': 'D#'}>", $H(Fixtures.many).inspect());
     }},
+
+    testClone: function(){ with(this) {
+      var h = $H(Fixtures.many);
+      assertHashEqual(h, h.clone());
+      assertInstanceOf(Hash, h.clone());
+      assertNotIdentical(h, h.clone());
+    }},
     
     testToJSON: function(){ with(this) {
       assertEqual('{\"b\": [false, true], \"c\": {\"a\": \"hello!\"}}',
         $H({'b': [undefined, false, true, undefined], c: {a: 'hello!'}}).toJSON());
-
-      assertEqual('E', eval('(' + $H(Fixtures.dangerous).toJSON() + ')')._each);
     }}
   }, 'testlog');
 // ]]>
diff --git a/test/unit/unit_tests.html b/test/unit/unit_tests.html
index d21a42a..b98ed27 100644
--- a/test/unit/unit_tests.html
+++ b/test/unit/unit_tests.html
@@ -58,7 +58,7 @@
     testIsRunningFromRake:  function() { with(this) {
       if (window.location.toString().startsWith('http')) {
         assert(isRunningFromRake);
-        info('These tests are runingn from rake.')
+        info('These tests are running from rake.')
       } else {
         assert(!isRunningFromRake);
         info('These tests are *not* running from rake.')