The watch trick is relatively easy to do.. With an older watch, if you knock it hard against the wrist, the battery will come off the contacts therefore it's not getting any power, and it doesn't work.. Another way to do it is to have a relatively good magnet in your hand while the watch goes on your wrist. (But how many people carry a good magnet with them wherever they go?)

As for the clock issue, that's quite odd.. But in Canada, Walmart dose sell the wind up variety (So dose Ikea)..

There are also these nifty watches out that use your body's natural motion to power the thing.. By moving you cause a weighted dial to rotate, like a mini generator within the watch.. But there really hard to come by and VERY expensive.. I got one for a Christmas gift.. No chance of it having battery problems..