Hmm... try having an art sale? Draw pictures and paint them, or if you're not a great drawer, try abstract. The only problem is painting and making the pictures takes a long time, and people may not pay too high for them unless you put them up on EBay or somewhere where a lot of people will see them.
Find random objects and go door-to-door selling. It sounds crazy, and certainly odd, yes, but I made about $10 doing that once. I found stuff laying in the street (that people had obviously thrown away) and just walked around asking people to make their bids. I think they just bought them 'cause they felt sorry for me. Imagine a 10 year old comming to your door and asking you if you'd like to buy nails (like you hit with a hammer).
If you live in a city (or a place with a good population) do a street act. If you play an instrument, set out a suitcase or something for people to drop money in and play songs for them. Juggle, if you know how, or even do gymnastic stunts. Practically any little talent would work.