PLEN is a desktop hobby robot made in Japan that can balance on a proportional skateboard and rollerskate on its own.   It has 18 joints which are controlled remotely by a Bluetooth phone and keeps a charge up to 25 minutes at a time.

The site is in Japanese, but the videos of PLEN in action are a must-see.  Even if you can't afford the over $2000 price tag, you can still gawk at it and drool.  (Go to the site and click on Gallery to view the videos.)

[via technabob]