module ActionController::Caching::Pages

def cache_page(content = nil, options = nil)

cache_page "I'm the cached content", :controller => "lists", :action => "show"
If no options are provided, the requested url is used. Example:
Manually cache the +content+ in the key determined by +options+. If no content is provided, the contents of response.body is used 
def cache_page(content = nil, options = nil)
  return unless self.class.perform_caching && caching_allowed
  path = case options
    when Hash
      url_for(options.merge(:only_path => true, :format => params[:format]))
    when String
      options
    else
      request.path
  end
  self.class.cache_page(content || response.body, path)
end