diff --git a/actionpack/CHANGELOG b/actionpack/CHANGELOG
index afe9a4e6bcb481edd0d9277cda693427c3d7b165..ff2315fc3c7b1d64970b9746174a3367ac7261c2 100644
--- a/actionpack/CHANGELOG
+++ b/actionpack/CHANGELOG
@@ -7,7 +7,7 @@
         @posts = Post.find :all
   
         respond_to do |type|
-          type.html { render } # renders weblog/index.rhtml
+          type.html # using defaults, which will render weblog/index.rhtml
           type.xml  { render :action => "index.rxml" }
           type.js   { render :action => "index.rjs" }
         end
diff --git a/actionpack/lib/action_controller/mime_responds.rb b/actionpack/lib/action_controller/mime_responds.rb
index 42b6e242050343e99b9e3ca808047b2bd4b2d1d3..e8d1ba089bda91c100174db968f3ccee577f46db 100644
--- a/actionpack/lib/action_controller/mime_responds.rb
+++ b/actionpack/lib/action_controller/mime_responds.rb
@@ -13,6 +13,13 @@ def respond_to(&block)
     end
     
     class Responder #:nodoc:
+      DEFAULT_BLOCKS = {
+        :html    => 'Proc.new { render }',
+        :js      => 'Proc.new { render :action => "#{action_name}.rjs" }',
+        :xml     => 'Proc.new { render :action => "#{action_name}.rxml" }',
+        :xml_arg => 'Proc.new { render :xml => __mime_responder_arg__ }'
+      }
+      
       def initialize(block_binding)
         @block_binding = block_binding
         @mime_type_priority = eval("request.accepts", block_binding)
@@ -22,9 +29,19 @@ def initialize(block_binding)
       
       for mime_type in %w( all html js xml rss atom yaml )
         eval <<-EOT
-          def #{mime_type}(&block)
+          def #{mime_type}(argument = nil, &block)
             @order << Mime::#{mime_type.upcase}
-            @responses[Mime::#{mime_type.upcase}] = block
+            
+            if block_given?
+              @responses[Mime::#{mime_type.upcase}] = block
+            else
+              if argument
+                eval("__mime_responder_arg__ = " + (argument.is_a?(String) ? "'" + argument + "'" : argument), @block_binding)
+                @responses[Mime::#{mime_type.upcase}] = eval(DEFAULT_BLOCKS[(Mime::#{mime_type.upcase}.to_sym.to_s + "_arg").to_sym], @block_binding)
+              else
+                @responses[Mime::#{mime_type.upcase}] = eval(DEFAULT_BLOCKS[Mime::#{mime_type.upcase}.to_sym], @block_binding)
+              end
+            end
           end
         EOT
       end
diff --git a/actionpack/test/controller/mime_responds_test.rb b/actionpack/test/controller/mime_responds_test.rb
index d78feb25e9ea7887164b3971694f1aae3be6fc2e..f2aa45a168d8f1d3d0ffab89d77bd6ce4b58a6e3 100644
--- a/actionpack/test/controller/mime_responds_test.rb
+++ b/actionpack/test/controller/mime_responds_test.rb
@@ -31,12 +31,30 @@ def just_xml
       type.xml  { render :text => "XML" }
     end
   end
+  
+  def using_defaults
+    respond_to do |type|
+      type.html
+      type.js
+      type.xml
+    end
+  end
+  
+  def using_argument_defaults
+    person_in_xml = { :name => "David" }.to_xml(:root => "person")
+    respond_to do |type|
+      type.html
+      type.xml(person_in_xml)
+    end
+  end
 
   def rescue_action(e)
     raise unless ActionController::MissingTemplate === e
   end
 end
 
+RespondToController.template_root = File.dirname(__FILE__) + "/../fixtures/"
+
 class MimeControllerTest < Test::Unit::TestCase
   def setup
     @request    = ActionController::TestRequest.new
@@ -99,4 +117,24 @@ def test_js_or_anything
     get :just_xml
     assert_equal 'XML', @response.body
   end
+  
+  def test_using_defaults
+    @request.env["HTTP_ACCEPT"] = "*/*"
+    get :using_defaults
+    assert_equal 'Hello world!', @response.body
+
+    @request.env["HTTP_ACCEPT"] = "text/javascript"
+    get :using_defaults
+    assert_equal "$('body').visualEffect(\"highlight\");", @response.body
+
+    @request.env["HTTP_ACCEPT"] = "application/xml"
+    get :using_defaults
+    assert_equal "<p>Hello world!</p>\n", @response.body
+  end
+  
+  def test_using_argument_defaults
+    @request.env["HTTP_ACCEPT"] = "application/xml"
+    get :using_argument_defaults
+    assert_equal "<?xml version=\"1.0\" encoding=\"UTF-8\"?>\n<person>\n  <name>David</name>\n</person>\n", @response.body
+  end
 end
\ No newline at end of file
diff --git a/actionpack/test/controller/new_render_test.rb b/actionpack/test/controller/new_render_test.rb
index 8359e190a071a02a098e17b9c559bcb8873a1ae6..5bdb8ec7f8b0c997eb9ef1e5c505003ad7ae6b07 100644
--- a/actionpack/test/controller/new_render_test.rb
+++ b/actionpack/test/controller/new_render_test.rb
@@ -184,6 +184,14 @@ def @template.name() nil end
     render :action => "potential_conflicts"
   end
 
+  def hello_world_from_rxml_using_action
+    render :action => "hello_world.rxml"
+  end
+
+  def hello_world_from_rxml_using_template
+    render :template => "test/hello_world.rxml"
+  end
+
   helper NewRenderTestHelper
   helper do 
     def rjs_helper_method(value)
@@ -560,4 +568,13 @@ def test_yield_content_for
     get :yield_content_for
     assert_equal "<title>Putting stuff in the title!</title>\n\nGreat stuff!\n", @response.body
   end
-end
+
+
+  def test_overwritting_rendering_relative_file_with_extension
+    get :hello_world_from_rxml_using_template
+    assert_equal "<html>\n  <p>Hello</p>\n</html>\n", @response.body
+
+    get :hello_world_from_rxml_using_action
+    assert_equal "<html>\n  <p>Hello</p>\n</html>\n", @response.body
+  end
+end
\ No newline at end of file
diff --git a/actionpack/test/controller/render_test.rb b/actionpack/test/controller/render_test.rb
index db6f71acc9a9152ca0b086d5fedf9aa8c8816201..1ee77a549d23534e2d66dbfad7af64dbd05435b5 100644
--- a/actionpack/test/controller/render_test.rb
+++ b/actionpack/test/controller/render_test.rb
@@ -18,14 +18,6 @@ class TestController < ActionController::Base
   def hello_world
   end
 
-  def hello_world_from_rxml_using_action
-    render :action => "hello_world.rxml"
-  end
-
-  def hello_world_from_rxml_using_template
-    render :template => "test/hello_world.rxml"
-  end
-
   def render_hello_world
     render "test/hello_world"
   end
@@ -251,12 +243,4 @@ def test_accessing_local_assigns_in_inline_template_with_string_keys
     get :accessing_local_assigns_in_inline_template_with_string_keys, :local_name => "Local David"
     assert_equal "Goodbye, Local David", @response.body
   end
-
-  def test_overwritting_rendering_relative_file_with_extension
-    get :hello_world_from_rxml_using_template
-    assert_equal "<html>\n  <p>Hello</p>\n</html>\n", @response.body
-
-    get :hello_world_from_rxml_using_action
-    assert_equal "<html>\n  <p>Hello</p>\n</html>\n", @response.body
-  end
 end
diff --git a/actionpack/test/fixtures/respond_to/using_defaults.rhtml b/actionpack/test/fixtures/respond_to/using_defaults.rhtml
new file mode 100644
index 0000000000000000000000000000000000000000..6769dd60bdf536a83c9353272157893043e9f7d0
--- /dev/null
+++ b/actionpack/test/fixtures/respond_to/using_defaults.rhtml
@@ -0,0 +1 @@
+Hello world!
\ No newline at end of file
diff --git a/actionpack/test/fixtures/respond_to/using_defaults.rjs b/actionpack/test/fixtures/respond_to/using_defaults.rjs
new file mode 100644
index 0000000000000000000000000000000000000000..469fcd8e15ba81b98a5276da9e0e6dacc5993a63
--- /dev/null
+++ b/actionpack/test/fixtures/respond_to/using_defaults.rjs
@@ -0,0 +1 @@
+page[:body].visual_effect :highlight
\ No newline at end of file
diff --git a/actionpack/test/fixtures/respond_to/using_defaults.rxml b/actionpack/test/fixtures/respond_to/using_defaults.rxml
new file mode 100644
index 0000000000000000000000000000000000000000..598d62e2fca55941642ce03450df98f31b756565
--- /dev/null
+++ b/actionpack/test/fixtures/respond_to/using_defaults.rxml
@@ -0,0 +1 @@
+xml.p "Hello world!"
\ No newline at end of file