Sell stuff that's easy to ship on ebay!!!!!! It used to be just low priced items but you will make waaaaaay more than you will at a garage sale. It has saved me lately. And since you can list 50 items per month free, there is no risk! Only getting rid of stuff you don't want anyway! A good place to start is with video games, dvds, children's clothing. Those have sold very well for me!
I also do Secret Shopping. If you are detail oriented and can write well, you can find good work doing it. If you come across a company that wants you to pay them, DO NOT do it. It is a job, so you shouldn't be paying anyone. Only they pay you!
Lastly, try Amazon MTurk. Just make sure you answer accurately and honestly, as most of the stuff is for college psychology experiments. Good luck!