Go to the Fishing Pond, and make sure that you're lined up pretty well with the Fisherman behind the counter. Walk backwards into the water until the point if you back up anymore, you won't be able to cast. (You should be around shoulder-neck deep in water). Cast, and then it should land on the Fisherman's head--you have his hat! Beware, though--if you cast and his hat is still on the pole (if you haven't already given it back to him) you could lose it in the water--and then have to pay up fifty rupees to the fisherman for the hat! The fun thing about the glitch, though, you'll see, is that the Fisherman is bald!
