mTurk is a crowdsourcing site created by Amazon. There are a variety of tasks that you can do. Some of my favorites are surveys and data entry. My favorite task was one where I recorded words that I was saying. Payment ranges from $0.01 up to $2.50 (or that is the highest I have ever seen). One of the things that I love about mTurk is that there are always tasks available.
I will usually log on to mTurk while I am watching TV. I typically earn about $4 in one hour (it isn’t great but is extra money). There are some people that claim to make $10+ an hour
You can chose how you get your payment. I save mine up for purchases on Amazon.
If you are looking to earn a few extra dollars check out mTurk: https://www.mturk.com