We’ve covered some commercially available geek watches here in the past. But how about homebrewing one of your own?
Hardware hacker extraordinaire (and fellow Make advisory board member) Joe Grand has created a cool POV Watch (as in “persistence of vision”). An array of LEDs on the watch band will show the time when you shake your arm. Not sure if Joe’s going to release this one as a kit, like he did with his Electronic Game Kit.
While we’re giving Todd Bailey all of this free publicity (he of the PCB bizney card), we might as well show off his bitchin’ binary bling-bling, a homemade LED watch that uses a PIC16F872 microcontroller and has a ribbon cable for a wrist band. 
Instructions for making a similar LED watch can be found via this Make link.