I tried it as a skint student, down Portobello Road in London. After 15 minutes I was moved on by the police, but during the short time I was playing I earnt more than I could have done in an average job in a couple of hours (I forget the amounts but they would be meaningless today). I never tried it again though, it was just an impromptu thing because I just happened to be carrying my guitar home after a late night session somewhere, and it was a fine sunny day, and I thought, "why not?"