It's been a while since I talked about Opinion Outpost (full disclosure: that's my referral link), so I thought I'd mention it for newer readers who may not have seen it, or other survey sites, before.
Basically, it's a survey site that's free to join, and you can earn cash, Citi gift cards, OR Amazon e-certificates (which are redeemable instantly and are my favorite). You earn points for completing surveys - and a small number of points if you try but are ineligible. A typical survey might take 15 minutes to do and get you 20 points, or $2, which doesn't sound like a lot, but it adds up pretty quickly. They tailor the survey invitations you get to your lifestyle and interests, and sometimes you get to do fun things, like test beauty products or food and give them feedback on how you liked them.
There are plenty of other good survey sites besides Opinion Outpost out there if you look for them, many that pay in cash. Note: a legitimate site will never charge you to join up, will explain its rewards system clearly, and won't require you to participate in any "special offers" or "premium memberships." If you're going to waste time in front of your computer, you might as well be making money, right?