Amazon Mechanical Turk: I can’t believe I haven’t heard of this before, given that’s almost a year old.
Amazon’s MTurk service is an API to match people up with Human Intelligence Tasks (HITs) for them to complete and get paid.
HIT stands for Human Intelligence Task. These are tasks that people are willing to pay you to complete. For example a HIT might ask: “Is there a pizza parlour in this photograph?” Typically these tasks are extraordinarily difficult for computers, but simple for humans to answer.