Busking is informal street performance in exchange for money, etc. Like the guy who does the card tricks at Fisherman's Wharf or the Naked Cowboy in New York (He actually does wear briefs).
Anyway, last night I got a $5 bill. Cool. I think once last year I got a $10 bill. Those were exciting. But I've also gotten:
-Hong Kong Coins
-Susan B. Anthony dollars
-George Washington dollars
-"God Bless You"
-"Can you play the Sailor's Hornpipe?"
-"You're not homeless!"
-Solicited to go to an ACN convention.
-A card that said "make $50-150k per year! Call now!"
All of which may have been even more exciting. I don't do this for the money, but it's nice.