diff --git a/actionpack/CHANGELOG b/actionpack/CHANGELOG
index 2923232021134a83d6a1f536bdd68b226e0f7eab..69075f04db61bfc8bbebfb942cf689ee9aa5de77 100644
--- a/actionpack/CHANGELOG
+++ b/actionpack/CHANGELOG
@@ -1,5 +1,10 @@
 *SVN*
 
+* Added arrays as a value option for params in url_for and friends #467 [Eric Anderson]. Example:
+
+    url_for(:controller => 'user', :action => 'delete', :params => { 'username' =>  %( paul john steve ) } )
+    # => /user/delete?username[]=paul&username[]=john&username[]=steve
+
 * Fixed that controller tests can now assert on the use of cookies #466 [Alexey]
 
 * Fixed that send_file would "remember" all the files sent by adding to the headers again and again #458 [bitsweat]
diff --git a/actionpack/lib/action_controller/url_rewriter.rb b/actionpack/lib/action_controller/url_rewriter.rb
index 7bf9015b377b8c9c7e67538442fb32aa113f1279..fa003119ece77d70fb9ede61e453745cfd81d9c5 100644
--- a/actionpack/lib/action_controller/url_rewriter.rb
+++ b/actionpack/lib/action_controller/url_rewriter.rb
@@ -174,7 +174,12 @@ def build_query_string(hash)
         elements = []
         query_string = ""
 
-        hash.each { |key, value| elements << "#{CGI.escape(key)}=#{CGI.escape(value.to_s)}" }
+        hash.each do |key, value|
+	  key = CGI.escape key
+	  key += '[]' if value.class == Array
+	  value = [ value ] unless value.class == Array
+	  value.each { |val| elements << "#{key}=#{CGI.escape(val.to_s)}" }
+	end
         unless elements.empty? then query_string << ("?" + elements.join("&")) end
         
         return query_string
diff --git a/actionpack/test/controller/url_test.rb b/actionpack/test/controller/url_test.rb
index b595b1c25c5516e55639a6cbf864bef37f945781..8315830776c4557d0ebaf70dd3c0cf30dbb1a739 100644
--- a/actionpack/test/controller/url_test.rb
+++ b/actionpack/test/controller/url_test.rb
@@ -246,7 +246,18 @@ def test_parameters_with_id
       )
     end
   end
-  
+
+  def test_parameters_with_array
+    @clean_urls.each do |url|
+      assert_equal(
+        "http://www.singlefile.com/identity/show?id[]=3&id[]=5&id[]=10",
+	url.rewrite(
+		:action => "show",
+		:params => { 'id' => [ 3, 5, 10 ] } )
+      )
+    end
+  end
+
   def test_action_with_id
    assert_equal(
       "http://www.singlefile.com/identity/show/7",