While its merits as a keychain are questionable (not to mention potentially painful), these officially-licensed Atari
game-on-a-controller units from Basic Fun should prove to be geek catnip for anyone who remembers the good old days when game consoles were wood-paneled and had switches for black-and-white or color. The familiar 2600 joystick model is available in two variations, one with Asteroids and Millipede and one with Centipede and Yar's Revenge, while the paddle gives you Pong along with Breakout and Warlords -- although if the reviews are any indication you shouldn't expect completely faithful versions of the games. Each unit will set you back about $15, which includes the six foot RCA cable for connecting it to a TV (yeah, you gotta remember to tote that along with your keychain), but not the three AA batteries required to power it.
Read - Design Kitten Review
Read - Basic Fun