## view

  <%= sortable_element 'sortable_list',
    :update => 'pages',
    :url => update_positions_admin_pages_path,
    :handle => 'handle' %>

## controller

  def update_positions
    params["sortable_list"].each_with_index do |id, position|
      Page.update(id, :position => position+1)
    end
    render :nothing => true
  end

## routes.rb

  # Administration
  map.namespace :admin do |admin|
    ...
    admin.resources :pages, :collection => { :update_positions => :put }
    ...
  end

## development.log (correct routing to admin/pages controller)

Processing PagesController#update_positions (for 127.0.0.1 at 2008-05-14 11:50:23) [POST]
  Session ID: BAh7CToOcmV0dXJuX3RvMDoMY3NyZl9pZCIlNDJiODgxNGNlNTU5MmM2MmRh%0AY2Y0OTBlNjM2OWNjODYiCmZsYXNoSUM6J0FjdGlvbkNvbnRyb2xsZXI6OkZs%0AYXNoOjpGbGFzaEhhc2h7AAY6CkB1c2VkewA6DHVzZXJfaWRpBg%3D%3D--4029be28db1c3f53d6deae3f0ecdf3e0ecec3440
  Parameters: {"authenticity_token"=>"62c50cd2d3ae08a518c85e17850111aad0965c36", "action"=>"update_positions", "sortable_list"=>["1", "2", "3", "6", "4", "5"], "controller"=>"admin/pages"}

## production.log (incorrect routing to admin/pages as an ACTION)

Processing AdminController#pages (for 98.173.215.130 at 2008-05-14 13:51:19) [POST]
  Session ID: BAh7CToMY3NyZl9pZCIlMDc2Y2NhOGU4MTFiZDhjNzkzNWNiNzk2NzNjNzlm%0AYTM6DHVzZXJfaWRpBjoOcmV0dXJuX3RvMCIKZmxhc2hJQzonQWN0aW9uQ29u%0AdHJvbGxlcjo6Rmxhc2g6OkZsYXNoSGFzaHsABjoKQHVzZWR7AA%3D%3D--3d93637c4d089c3d28744b853831a78e7e9775a9
  Parameters: {"authenticity_token"=>"736ff9291c0421cf0ace7fe2cf65607b08353364", "action"=>"pages", "sortable_list"=>["1", "7", "3", "2", "4", "5", "6"], "id"=>"update_positions", "controller"=>"admin"}