I surprisingly get a lot of people asking to detail their car. I never intend to make a business of it, but I love doing it to my cars and people ask me to do it to theirs. All it takes is a cheap orbital buffer (mines a used craftsman) and a shop vac. I normally get easily $100 for a basic wash/wax/vac, or $200 to remove scratches and polish then wax the car.
Landscape. Look for brush-clearing, mowing, or woodcutting jobs, some of which may land you regular customers. This can save you money at the same time: if you are hired to pick up pine needles, use them to mulch your roses, which will appreciate their acidity and smothering effect on weeds; if you are hired to cut and clear a fallen tree, use it to heat your house that winter.