Are you thinking of mTurk where you do little jobs? It's hosted by Amazon. Just search mTurk and you'll find it. I've done a bit of it- mostly I transcribe receipts or take surveys.
I started around Christmas and when I was doing a little every night, I would make $10-$15 a week. I have made $175 so far. Since track season started, I've done very little. I mostly do surveys and receipt entry. Some surveys are .50 for less than 10 minutes. The time estimated or the time allowed isn't necessarily how long it will take you. I can make $3-6/hour when I find decent stuff and really try. To find the surveys, I go to the last page of hits and work backwards. Entering grocery receipts is better pay than it looks, because besides the base pay shown, you get bonuses the longer they are. I only do the receipts that are very easy to read and don't have lots of annoying discounts on every other line.
For me it's just a little Christmas spending money (I'll leave it in Amazon and spend it there), done when I don't have anything better to do.
Some assignments are better than others. For example, last week I did 200 assignments that took me, literally 8 seconds each and made 6 cents on each one, for about $7 in 20 minutes. I was doing it during downtime on my job so really had nothing better to do (The DIS was slow ;p)
The more jobs you have completed, the better assignments you become eligible for. I'm never going to make enough on mTurk to make a huge impact, but I can easily make $10 or 20 a week with very little effort.
Plus, some of them are fun! There are often jobs related to academic research, I always enjoy participating in those and knowing that I'm helping a grad student collect data.
I just signed up for mturk. I do swagbucks but there is nothing more frustrating than answering questions for a survey for 15 minutes and then being told you don't qualify for the survey! So I figure I'll do the minimum on swagbucks (a few searches, daily poll, sign into the toolbar) and then mturk. At least I am guaranteed that 1 cent for the survey I am really just doing both to supplement our Christmas money anyways.