They already did it many years ago with CRT monitors and LCD shutter glasses.
Now, they're doing it again with LCD monitors and LCD shutter glasses (nvidia 3d overpricedvision - empty wallet/small screen edition).
You can do 3D with any monitor and LCD shutter glasses (the cheapest "method" right now). It's just worse with a lot of monitors due to ghosting images, and it halves the monitor's refresh effectively, so 120hz LCD is preferred for 60FPS. 60hz LCD with 30FPS might be too flickery, although I haven't tried it personally.
If you're interested in purchasing shutter glasses to play in 3D, you can just do a search for "LCD 3d shutter glasses" and go from there.
I had shutter glasses 5 years ago or so, but gave them away. Ironically, of all games I played, I remember blood 2 the most out of playing with them
It was kind of awesome actually.
I'm waiting until they start making cheap 120hz LCD 37" monitors which can do 3D with glasses really well (no ghosting) before I try the technology again.
I think all these new 3DTVs are using prisms to separate right/left eye, or perhaps polarized or shutter glasses? IDK - haven't looked at them at all.
I don't think 3D is "the future" though. It's a nice gimmick, which I happen to like, but imo it's not going to become the norm, ever.
Edit: LOL, someone already beat me. Ironically, edimensional glasses is EXACTLY what I had 5-6 years ago. It's OLD, OLD, OLD tech... but it works :-D. As for price, ebay is your friend ;-). Bought mine for ~$40 if I remember correctly (YEARS ago in the CRT "era" still).