This is the page on ...This is the page on the website:
http://tvshack.net/movies/18_Year_Old_Virgin__2009_/
In the source code I found this:
flashvars="file=http://tweetypie.tvshack.net/zs/?id=NmY2OWYxZTRmMjQzMTNhMTJkMGIyMTliYmM0NzZiZjEuYjI4ek0yOHhOekE0T0Rn...
What the heck is tweetypie, is it some website service that allows you to get ZShare FLV?

No, its a subdomain they created. Noething more, they have a script their that connects to Zshare then gets the .flv url.
Which is quite easy, if you know your PHP and Javascript