Slotcars that you control by yelling into your phone, thanks to Asterisk and an Arduino. Pretty neat, and somewhat similar to a project that I finished not too long ago for our office's lobby (more on that soon). I wonder how he pulls apart the SIP VoIP stream...

The creator's other project is pretty cool, too — it uses Processing and cameraphones and image recognition to an interesting effect. I can't figure out how the hell one uses the mobot image recognition service that he refers to, though.

UPDATE: Check out this project, too, from the same show. With the number of bars and clubs that have prominent video displays, the low cost of the software (and VoIP service) and the ubiquity of cell phones, I really think a fun business could be made out of creating and selling machines that offer this kind of ad-hoc head-to-head gaming. I know I'd enjoy watching a projection of a few people play a game of Bomberman while waiting for the next band set up at a 9:30 show. Maybe the winner gets some money off his tab — it'd be great.