These are legit sites that I have personally received either gift cards or cash payment from. I am not making hundreds of dollars a month from them - but the little that I do get earns up over time.
1. Swagbucks - Swagbucks is a site that rewards you for searching among other things. Instead of using Google, Bing, or your Favorites, you swagbucks search what site you'd like to go on. A lot of my wins come from just typing Facebook and MSN into the swagbucks toolbar. You will randomly be awarded Swagbucks - ranging anywhere from 5 to 50. First step is the click the link above, set up your account and install their toolbar. The toolbar makes searching 10x easier. And you will get 1 swagbuck a day for having it. I will type up a blog post just about Swagbucks because this is just the tip of the iceberg.
2. E-rewards - Erewards is a survey based reward site. After you set up your account and fill out all of your profile information, they will Email you with survey that are available for you to take. You will not qualify for every survey they offer but even if you do not qualify you will get a small credit to your account. If you qualify, you will get a larger amount deposited into your Erewards account which you can trade in for a variety of things. I, personally, go for the $25 Target cards which you can redeem at $55 worth of Erewards. The gift cards come in about 1-2 weeks. I have been active with them for about 5 months and so far have earned $50 in Target giftcards and I'm close to my third.
3. MyPoints - Mypoints is a point based site. They have a search engine. For so many searches a month (they will tell you how many you need) you will earn 75 points a month. You can earn points through your online shopping, surveys, and by clicking Emails. They Email you offers, for just clicking that Email and going to the site you earn 5 points. If you take the offer you have the potential to earn even more points. If you are interested, I can Email out referral links.
4. Pinecone - Pinecone offers surveys for new products that are not yet available. They pay you $3 per survey and will deposit it directly into your Paypal account or mail you a check. There are also times where they will chose you to send the product to so that you can personally test it. You are not allowed to talk about the surveys or products to anyone outside if your household. The thing about Pinecone is that they only take new members at certain times. So they may not be open for new members at this time.
If you have any questions about any of these feel free to ask and I will answer them to the best of my knowledge. :)