diff --git a/lib/mongo/db.rb b/lib/mongo/db.rb
index 72048aa..7a3225b 100644
--- a/lib/mongo/db.rb
+++ b/lib/mongo/db.rb
@@ -89,6 +89,35 @@ module Mongo
       ok?(command(auth))
     end
 
+    # Adds a user to this database for use with authentication. If the user already
+    # exists in the system, the password will be updated.
+    #
+    # @param [String] username
+    # @param [String] password
+    #
+    # @return [Hash] an object representing the user.
+    def add_user(username, password)
+      users = self[SYSTEM_USER_COLLECTION]
+      user  = users.find_one({:user => username}) || {:user => username}
+      user['pwd'] = hash_password(username, password)
+      users.save(user)
+      return user
+    end
+
+    # Remove the given user from this database. Returns false if the user
+    # doesn't exist in the system.
+    #
+    # @param [String] username
+    #
+    # @return [Boolean]
+    def remove_user(username)
+      if self[SYSTEM_USER_COLLECTION].find_one({:user => username})
+        self[SYSTEM_USER_COLLECTION].remove({:user => username}, :safe => true)
+      else
+        return false
+      end
+    end
+
     # Deauthorizes use for this database for this connection.
     #
     # @raise [MongoDBError] if logging out fails.
diff --git a/test/test_db.rb b/test/test_db.rb
index f8c6fd8..92f2930 100644
--- a/test/test_db.rb
+++ b/test/test_db.rb
@@ -21,18 +21,6 @@ class DBTest < Test::Unit::TestCase
   @@db    = @@conn.db('ruby-mongo-test')
   @@users = @@db.collection('system.users')
 
-  def setup
-    @spongebob = 'spongebob'
-    @spongebob_password = 'squarepants'
-    @@users.remove
-    @@users.insert(:user => @spongebob, :pwd => @@db.send(:hash_password, @spongebob, @spongebob_password))
-  end
-
-  def teardown
-    @@users.remove if @@users
-    @@db.error
-  end
-
   def test_close
     @@conn.close
     assert !@@conn.connected?
@@ -139,9 +127,12 @@ class DBTest < Test::Unit::TestCase
   end
 
   def test_authenticate
+    @@db.add_user('spongebob', 'squarepants')
     assert !@@db.authenticate('nobody', 'nopassword')
-    assert !@@db.authenticate(@spongebob, 'squareliederhosen')
-    assert @@db.authenticate(@spongebob, @spongebob_password)
+    assert !@@db.authenticate('spongebob' , 'squareliederhosen')
+    assert @@db.authenticate('spongebob', 'squarepants')
+    @@db.logout
+    @@db.remove_user('spongebob')
   end
 
   def test_logout
@@ -202,6 +193,19 @@ class DBTest < Test::Unit::TestCase
     assert db.collection('users').remove
   end
 
+  def test_user_management
+    @@db.add_user("bob", "secret")
+    @@db.logout
+    p @@users.find.to_a
+    assert @@db.authenticate("bob", "secret")
+    assert @@db.remove_user("bob")
+    assert !@@db.authenticate("bob", "secret")
+  end
+
+  def test_remove_non_existant_user
+    assert !@@db.remove_user("joe")
+  end
+
   context "database profiling" do
     setup do
       @db  = @@conn['ruby-mongo-test-admin-functions']