First introduced in early 2003, the OnHandPC has just been discontinued. This nifty gadget combined a digital watch, scheduler, expense manager, calculator, timer, games, and more, all into a small PDA watch. The emergence of Smartphones most likely contributed to its demise.
From the article: “The OnHandPC has the power and memory of a Palm m100 in the size of a wrist watch. Batteries last up to several months which is pretty good compared to other devices like a Palm.”