This may include mere copy-pasting, minor text editing, data categorisation, translations and staff alike. You can work a few hours a day and earn some hundred bucks by the end of the month. Obviously, the total payout depends on how fast/good you are. Sign up to ClickWorker if you can tolerate handling some routine tasks in exchange for cash injections.
One of the cool things about Google AdSense is that it's so easy to get set up. If you have a blog or website, you can sign up for a free Google AdSense Account. From there, Google will give you a unique code that you will paste onto your website. Google takes it from there, tracking your page views, traffic, and earnings on your behalf. There is no upkeep or maintenance to get this thing going, which makes it a no-brainer if you have a website already.