I'd probably feel a bit guilty about it but i'd keep it and spend it anyway.
Easy. Hand it in to the Police. It's the right thing to do.
I'd give the case to charity so other people can benefit!
Mwahaha! The money is mine! Finders keepers, losers weepers. Suck on that!
I'd keep the money but spend it on family and friends.
Use the money to take Loony Bob and Psychotic out on a date!
I'd probably feel a bit guilty about it but i'd keep it and spend it anyway.