So instead of using an external monitor hookup, I use an old laptop that I hook up to a second (and third monitor). Install Maxivista on both laptops and now you can "share" monitors. Basically the monitors on the second PC are remote monitors.

Hard to explain but the best tool I have seen in years!!!

here is a link to some more info and my setup!

http://www.facebook.com/note.php?note_id=6624689369

Ciao!