Quality keychain watch?

[heathen]

Hi folks I'm searching for a high quality watch that could be clipped onto my keys. It would need to be pretty tough to withstand the constant rubbing against the keys and other junk in my pocket and hopefully water resistant enough to survive at least a dunking. It could be analog or digital and doesn't really have to have any special features, although having the date would be nice. I would prefer something very small, say the size of Photon microlight, but I realize that I probably won't find anything that small. Anybody know of anything like this? Thanks very much, Heath