form_remote_for & file uploads

Has anyone successfully gotten Ajax file uploads working using form_remote_for & attachment_fu? I have seen Sean Treadway's responds_to_parent plugin and many other samples available, and they all seen to statically generate <form> tags. Is there a way to get a file upload to work using the Rails helpers?

<% form_remote_for(:message, @message, :url => contacts_messages_path(contact), :method => :post, :html => {:multipart => :true, :id => "new_message_form", :target => "frame"}) do |f| %> <iframe id='frame' name="frame" style="display:none;"></iframe> ...fields... <% end %>

Help is appreciated.

- j