If getting paid to test out apps seems like a great way to spend your time, AppCasher will be right up your alley. You can earn credit for installing and launching apps, and these credits can then be converted into gift cards that you can use to buy things from Amazon or iTunes. You can opt to have cash transferred to your PayPal account instead.
You can also refer your friends to the app and, providing they use your special code, you'll earn extra credit for each person who signs up.