Interesting blog entry on the Foreui mockup tool blog about a service that is free for now which generated either Balsamiq or Foreui meta file from an existing web page. The author tried it on the front page of Linkedin with some success. I tried it on the front page of Dzone with quite a bit less luck. http://www.foreui.com/blog/?p=1065
Here is a direct link to the tools homepage: http://www.looksie.me/