Crowdology looks fantastic and is super easy to sign up. Of course, it's totally free.
Whether you have just a couple of minutes to spare or a bit more time, Crowdology offers paid online surveys that fit in with your day. Their surveys generally take between 2 and 15 minutes to complete, depending on the topic. So you can make extra money every time you fill one out.
Cash in with each survey you complete and cash out with PayPal or Amazon vouchers.