Check out this amazing homebrew Pong watch made by John Maushammer, the hacker who open firmware for the Pure Digital "disposable" cameras.
I loved the idea behind the Pong Clock and I've wanted to make my own watch for a while now… combine those two things, and I've got a start at the Pong Watch. This is just an electrical prototype – the hard part will be making the watch case and then squeezing all the electronics in there. The display is a small (1.2") 96×64 yellow-and-white OLED display. OLEDs are neat because only consume power proportional to the number of pixels that are turned on — for a game like pong, that's a relatively small 1-2% of the display, so the power requirements are pretty small. Plus, the high contrast looks great with a game like this. I haven't worked out the power budget in detail yet, but hopefully I can get a day's use out of the watch, and then recharge the battery each night. The charger would also automatically set the time, so there will be no need for buttons on the watch.
