When companies create new websites, they need people to test them and give feedback on the functionality, speed, ease-of-use, etc., and there are companies that will pay you to do so. Once such company is UserTesting. You may even be able to find companies directly that will pay you to test their websites. UserTesting pays its testers $10 every time they review a site. Some of the tests are only 15 to 20 minutes long and they pay through PayPal. They choose testers by their demographics, and there are lots of testers on board so you may not always get work from them. You have to complete an audio test sample, so you will need a microphone.
Another website testing company is WhatUsersDo. They pay $8 and up for 15 to 20 minute tests and you will also need a microphone and a Paypal account for this one. Another is YouEye, where you can earn an average of $25 per session which is usually around 20 minutes. Lastly, there is Analysia, which pays $10 for 10 to 15 minute tests, and they also pay through PayPal. This is just a sampling of what is available for website testing.