diff --git a/CREDITS b/CREDITS
new file mode 100644
index 0000000..afa28b2
--- /dev/null
+++ b/CREDITS
@@ -0,0 +1,60 @@
+Adrian Madrid, aemadrid@gmail.com
+* bin/mongo_console
+* examples/benchmarks.rb
+* examples/irb.rb
+* Modifications to examples/simple.rb
+* Found plenty of bugs and missing features.
+* Ruby 1.9 support.
+* Gem support.
+* Many other code suggestions and improvements.
+
+Aman Gupta, aman@tmm1.net
+* Collection#save
+
+Jon Crosby, jon@joncrosby.me
+* Some code clean-up
+
+John Nunemaker, http://railstips.org
+* Collection#create_index takes symbols as well as strings
+* Fix for Collection#save
+* Add logger convenience methods to connection and database
+
+David James, djames@sunlightfoundation.com
+* Fix dates to return as UTC
+
+Paul Dlug, paul.dlug@gmail.com
+* Generate _id on the client side if not provided
+* Collection#insert and Collection#save return _id
+
+Durran Jordan, durran@gmail.com
+* DB#collections
+* Support for specifying sort order as array of [key, direction] pairs
+
+Cyril Mougel, cyril.mougel@gmail.com
+* Initial logging support
+* Test case
+
+Jack Chen, chendo on github
+* Test case + fix for deserializing pre-epoch Time instances
+
+Michael Bernstein, mrb on github
+* #sort method for Cursor instances
+
+Paulo Ahahgon, pahagon on github
+* removed hard limit
+
+Les Hill, leshill on github
+* OrderedHash#each returns self
+
+Sean Cribbs, seancribbs on github
+* Modify standard_benchmark to allow profiling
+
+Sunny Hirai
+* Suggested hashcode fix for Mongo::ObjectID
+* Noted index ordering bug.
+
+Christos Trochalakis
+* Added map/reduce helper
+
+Blythe Dunham
+* Added finalize option to map/reduce
diff --git a/README.rdoc b/README.rdoc
index 3b7c267..669bafa 100644
--- a/README.rdoc
+++ b/README.rdoc
@@ -329,63 +329,7 @@ See HISTORY.
 
 = Credits
 
-Adrian Madrid, aemadrid@gmail.com
-* bin/mongo_console
-* examples/benchmarks.rb
-* examples/irb.rb
-* Modifications to examples/simple.rb
-* Found plenty of bugs and missing features.
-* Ruby 1.9 support.
-* Gem support.
-* Many other code suggestions and improvements.
-
-Aman Gupta, aman@tmm1.net
-* Collection#save
-
-Jon Crosby, jon@joncrosby.me
-* Some code clean-up
-
-John Nunemaker, http://railstips.org
-* Collection#create_index takes symbols as well as strings
-* Fix for Collection#save
-* Add logger convenience methods to connection and database
-
-David James, djames@sunlightfoundation.com
-* Fix dates to return as UTC
-
-Paul Dlug, paul.dlug@gmail.com
-* Generate _id on the client side if not provided
-* Collection#insert and Collection#save return _id
-
-Durran Jordan, durran@gmail.com
-* DB#collections
-* Support for specifying sort order as array of [key, direction] pairs
-
-Cyril Mougel, cyril.mougel@gmail.com
-* Initial logging support
-* Test case
-
-Jack Chen, chendo on github
-* Test case + fix for deserializing pre-epoch Time instances
-
-Michael Bernstein, mrb on github
-* #sort method for Cursor instances
-
-Paulo Ahahgon, pahagon on github
-* removed hard limit
-
-Les Hill, leshill on github
-* OrderedHash#each returns self
-
-Sean Cribbs, seancribbs on github
-* Modify standard_benchmark to allow profiling
-
-Sunny Hirai
-* Suggested hashcode fix for Mongo::ObjectID
-* Noted index ordering bug.
-
-Christos Trochalakis
-* Added map/reduce helper
+See CREDITS
 
 = License
 
diff --git a/lib/mongo/collection.rb b/lib/mongo/collection.rb
index b0f62d7..84b2f81 100644
--- a/lib/mongo/collection.rb
+++ b/lib/mongo/collection.rb
@@ -338,11 +338,14 @@ module Mongo
     # Performs a group query, similar to the 'SQL GROUP BY' operation.
     # Returns an array of grouped items.
     #
-    # :keys :: Array of fields to group by
+    # :keys :: an array of fields to group by
     # :condition :: specification of rows to be considered (as a 'find'
     #               query specification)
     # :initial :: initial value of the aggregation counter object
     # :reduce :: aggregation function as a JavaScript string
+    # :finalize :: optional. a JavaScript function that receives and modifies 
+    #              each of the resultant grouped objects. Available only when group is run
+    #              with command set to true.
     # :command :: if true, run the group as a command instead of in an
     #             eval - it is likely that this option will eventually be
     #             deprecated and all groups will be run as commands
@@ -381,7 +384,8 @@ module Mongo
         end
       end
 
-      raise OperationFailure, "finalize is only supported with the group command" if finalize
+      raise OperationFailure, ":finalize can be specified only when " +
+        "group is run as a command (set command param to true)" if finalize
 
       case reduce
       when Code