The Phantiq Video Game Projector V.3 is a very low-cost portable projector selling for just $179.99 via Amazon.com.

At 180 bucks you cannot expect top specifications, but possibly this projector is good enough for casual video game parties.
The Phantiq Video Game Projector V.3 only has composite video inputs and ships already with a cable that works with the Nitendo Wii. Specifications of this low-cost projectors include 12-80 inch projection size, 962 x 240px resolution, 80-120 ANSI lumen brightness (you need a very dark room), 200:1 contrast ratio and integrated 2W speakers.

To connect a Wii or PS2 to this projector is ok, but it would be crazy to connect it to a high resolution console like the Xbox 360 or Sony PS3.