Slicethepie.com : Review music, get paid via Paypal when you reach $10 minimum. Sign up is free and you should be able to start right away, though I hear it has been a little more difficult of late to get into 'review rooms' as more people sign up. Also, the better your reviews, the more you will make. I have not used this site, so I am only going by what I have researched online. It appears to be legitimate and people are making some 'fun' money with the site.
Webanswers.com: You answer or ask questions for others to answer. Sign up is free. It appears this is a revenue-sharing type of site, where you will earn money via adsense ads placed on your answer page. I have not tried it, but again it appears to be legitimate, easy enough to get started, and you may make residual income without too much effort. But again, do not expect to make much more than a little 'fun' money.
Amazon Mechanical Turk (MTurk): This is a 'crowdsource' program where you earn money online by performing basic tasks (known as "Hits") for employers (known as "Requesters"). You can be paid either in the form of cash (which Amazon pays into your bank account, or by purchasing Amazon gift cards which you can spend at their wesite. Many people say they make decent regular income with MTurk while others use it in their spare time to make a few extra dollars each week. I have signed up and have made some money right away. It is very legitimate and a nice stream of income to have at your disposal for when you want to work from home at night or during the day when your little ones are playing or sleeping.
Fiverr.com: Probably most of you have already tried this site or have heard of it anyway. But I added it here in case you have forgotten about it or have yet to try it out. It is free to join, easy to list a task, and you can make some fun money with the site. Check around-there are other sites like this popping up as well. But be careful to research and make sure others are legit.
Usabilty Testing Sites: There are various sites around where you can get paid to visit websites and complete a task (so as to garner feedback for that website's owner.) Competition can be tough - so you may want to sign up with more than one of these types of sites. Here are a couple to get you started:
Clickworker.com: This is another site that pays for you to complete short tasks, ranging from writing, researching, copywriting and easier tasks as well. The very nice thing with Clickworker is that they pay every week, even if you have one cent in your account! It is free to sign up, after which you will need to complete some assessment testing in order to select tasks.
CloudCrowd.com: Another get paid to complete task site. You are paid the next business day after completing a task. They also offer a very nice referral program giving you additional opportunities to earn money. You will find and complete all jobs via their Facebook application. Each task at CloudCrowd is reviewed by another worker. On some tasks you might do work and on other tasks you might review the work of others.