I know that on manual ones the top winds up a spring that stores energy, (in electric ones there's a motor instead), and that there's all sorts of gears, the ratio between gears makes different rotational speeds (like on a bike), and /something/ keeps the spring in a manual one from simply dumping all its energy into the watch at once, but past that I have very little clue how one actually /works/.
I bet all those little tiny gears and stuff are /really/ hard to make and assemble, though...
Anyone know anything about all this crazy stuff??