Saw this and figured I could go this route when I retire or if things ever got really bad.  Maybe you've seen him; nevertheless, enjoy these two videos of the same guy.

#1  http://youtube.com/watch?v=FBcvBeg7uXY

#2  http://youtube.com/watch?v=R6_-eFH6ed4&feature=related

Note: This guy is actually supposed to have gotten his start in drum corps and evidently plays set in various tribute bands.

I have seen a few people like this in and around downtown Austin and San Antonio when I have been there at different times. It has never been the same guy though, its always someone new.

I wouldn't do it alone.  I would have someone watching my back and my donation can/box.  I've had students pull out their instrument on tour (drum corps and band) and make $20+ in an hour.  Not bad; but again, they had someone watching over them while they played.

When I retire, I would like to teach computer science and high level math (calculus, linear algebra, etc) at a high school.

Call me boring I guess :P

The guy in the video probably made $10+ in those two minutes. 

Street performers make pretty good money if they work the right location.�� There's a folk guitarist in LA that sits outside a busy movie theater, and I watched him drive off in his new Mustang GT.�� I also saw a guy who plays the flute in Waikiki drive away in a Lexus after he filled a duffle-bag.��

Years ago Mn Brass Inc. played at a Vikings game and I made $11 just drumming my way to my car parked outside on the street.�� It made me want to buy my own quads and drum where drunk people congregate.