Make extra money with Amazon Mechanical Turk (AKA MTurk) in your free time. Complete HITs (Human Intelligence Tasks) according to the posted instructions. HITs can vary from completing a survey, to identifying objects in a picture, to transcribing audio recordings, etc.
The HIT requester will decide within 30 days whether to approve the task you completed and pay you for it. So be sure to complete the task thoroughly and correctly. When payments are made, you can transfer them to your Amazon Payments account, an Amazon.com gift card, or to a bank account (depending on the country you are from).
The availability of tasks may be limited at times, or offer low compensation for the time required. Be sure to check the list of HITs regularly for new opportunities.