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.
Mechanical Turk: Amazon's Mechanical Turk is a resource for doing human-intelligence tasks, or as the site commonly refers to them, HITs. You get paid a very small fee for any given HIT and you'll need a good deal of volume to make a substantial amount of money. But it is a resource you can use in your spare time to generate a small income online. 
With one of the lowest cash limits in the industry, you can get $10 out when you have accrued just 100 points. If you want to take your earnings in the form of a giftcard, the threshold is even lower, as you just need 50 points, equivalent to $5. Many other survey sites will only pay out after you earn much more, like $50. As with all good survey sites, Opinion Outpost allows you to take your earnings away in vouchers for big firms like Amazon or iTunes, or if you prefer money, to do so through Paypal. As well as paying out early Opinion Outpost also pays extremely quickly, often the same day or in some cases, immediately.