One long talked about form of making money on the side is Plasma. You've probably heard of it, but there are a few looked over benefits of braving the needle and spending an hour or two in the chair.
1. In some places you can make up to $300 a month.
2. Money payback is immediate
3. Most places are fairly accessable
4. You can feel good knowing that your plasma is going to a good cause
A good website to learn more about donating plasma in your area is: http://www.biolifeplasma.com/html/getting_started/getting_started.html