...It is really cool to see people sit on the piano and play, it is mostly children who obviously take piano lessons. I've sat down put a hat on the floor as a joke and got some gold coins woot!
Busking is a blast, provided the authorities don't get on your case. Years ago I used to do it from time to time in Boston subway stations, singing mostly my own stuff but covering other people too. Usually made enough to cover the day's meals, anyway (not that they were anything fancy!)