I tend to keep a couple hundred extra lying around just in case my family does something stupid and needs me to bail them out, but that's happened way too many times in the past couple of months and I laid the law down to them the last time it happened- the response now will be: go fuck yourself and get a job, you asshole.
I'm kind of torn between wanting to go on a stupid, extravagant spending spree with my bonus check and probably needing to sock away a little bit more cash for moving after school is done next May, but I'll probably piss it all away because that way if they do come (which they will) whining about bills needing to be paid, I can just stroke my shiny new electronics purchase while I tell them to fuck themselves.