Yeah, as someone else said, you might want to look into refereeing / umpiring..
During the summer, I'll have several jobs.. but the best income will be umpiring. During the summer, I do about 5 games in a row paying at $25 / game. So, you total it up and I'm making $125 / day when I do that.
You might also want to look into applying special skills you have, like technical work or web design. I do both, and I advertise for myself mostly. When I do either, the money is very good.