Add this to your ApplicationController to get a linking data style url handling (force usage of 'format' in URLs)

Linking Data style Rails applications

  before_filter :ensure_extension

  # Force an extension to every url. (LD)
  def ensure_extension
    redirect_to url_for(:format => (request.format && request.format.symbol) || :html) unless params[:format]
  end

  # Set a default value for the :format parameter in url_for and *_url/*_path methods.
  def default_url_options(options = nil)
    {:format => params[:format]}.merge(options || {})
  end