Eons ago I picked up a Loel video card. It had some strange video system that let you do multi monitor stuff just like windows, IE mouse pointer move from one screen to the other w/o switching anything.
I think it was called TIGA and it only works with certain programs and that specific card. It WAS cool though...
**EDIT**
Ok, just checked up on the BBoH, and the CARD was called TIGA, nicknamed the Lowell. No clue what the software package was called...