If you've got an Nvidia card, you could get 3D vision (both anaglyph and the new kind) in games for free.
they've got a list of compatible cards on the site (
http://www.nvidia.com/object/3d-vision-requirements.html)
Killing Floor, Split/Second and Metro 2033 look sweet with my anaglyph glasses. you get the 3D feel, but the colours are darker and stuff.
Thanks for the link Gabya, and... What The?
NEC

, Wasn't expecting that...