I have tried a few online sites to make some extra cash. Obviously one of the biggest is eBay.
I am going to go through some video games and clothes today and set up a few listings on eBay.
I also joined www.inboxdollars.com but you have to reach $30 for them to send a check and it can take a while to get there.
I am trying www.heliumknowledge.com which pays for you to post what you know or give your opinion. I am not sure yet if this is profitable.
If you are crafty, try www.etsy.com or www.hyenacart.com
I am going to look through some others today. It gets a little frustrating trying to read through them all and see if there is proof of money made, etc... but I am trucking along!