plasma, sperm, find a temp job, burn CDs for friends, grab a university newspaper and volunteer for studies, ask random grannies with messy lawns if you can fix it up, scribble randome crap and post them for sale on Deviant Art Prints, roam through college towns & grab kegs you see & sell them to liquor stores for $5-$10 each, if you have a MMORPG game waste a few hours camping a rare item then sell it on gaming auctions, pretend you're a DJ and play music for grannies for a few hundred with your computer and speakers, offer to cut people's hair for $2 or $3 and watch the poor college students flock to you, visit your messiest friend and offer to clean their place for cash, buy stuff from Goodwill and then sell them in a garage sale for more cash, anddd... thats all I can think of