My last name is "Burch" so I made Burch Bucks.
I photoshopped a dollar with a really silly photo of myself instead of
George Washington and copied it on green paper. When a kid does
something exceptionally well (like clean up a mess he or she didn't
make, or take it upon his/herself to clean out the sink, etc...) they
get a Burch Buck. They can use Burch Bucks to buy art supplies, trips
to the restroom/fountain, or they can save them up to use as extra
credit at the end of the term.
Of course, lost/stolen Burch Bucks are just like cash... if they don't
have them to spend, they can't spend them. I can usually tell when a
kid brings a Buck that isn't his or hers... but the kids must take
responsibility for their own "cash."
They love this, and everyone gets a laugh from the silly dollar I made.