Go around your house and put any unwanted books/CDs/cassettes/games on Amazon marketplace. Pretty easy money, but not instant for the most part. LiveJournal has some active selling communities as well, and Craig's List for some old stuff like furniture you might have in your basement or lying around you don't particularly need or use. Probably not what you meant, but it's certainly an easy way to clean up your house and make some money haha.
Opinion Place (only a few bucks here and there - but very easy. Have your choice of Paypal, Amazon GCs and more. Make sure you set for special invitation emails so you get more surveys, too. They usually give you your money within 2-3 weeks from taking a survey, but are reallly good.)
Opinion Outpost (also only a few bucks here and there, but seems to get a lot more surveys. Unfortunately, they only cut you a check and not Paypal direct deposit.)
SayNation (surveys for GCs or Paypal credit, takes awhile to build credit here but they do have daily surveys. i've received a few Amazon GCs.)
You could also do Trainn referral sites and pay people $20/referral or something, and get the cash prizes. Like pay $140 to your referrals to get $350 cash prize or something. Pretty easy profit.
Anything4Free can help with that, as well as the referral forum here.