Do you have an nVidia 8xxx series or higher card?
Well, using the method I'm about to link to, you can play games in 3D without needing a supported card or monitor.
I tried it playing Left 4 Dead in 3D today, and it's just amazing.
http://gamerslastwill.com/2009/02/02/3d-left-4-dead-for-free-oh-yeah-heres-how/Some notes:
You need 3D glasses, any of the following will work:
Red & Blue
Red & Green
Yellow & Blue
Polarized glass (gray) that you get at movie theaters will NOT work.
Also, your game needs to be running in full screen mode. That means no windowed+noborder for orangebox games (at least when you're playing in 3D)
Here's a list of games it works with:
http://www.nvidia.com/object/GeForce_3D_Vision_3D_Games.html