Earning some spare change
I don't know if people remember the programs you'd download to your computer that worked when it was idle to find aliens or map proteins, but there's a new version of that program that does research which is paid for, the money is then sent to the people whose computers are doing the processing. You won't make a ton of money, but if you are already leaving your computer on then you may as well sign up and earn a little bit of cash. Check it out by clicking on the icon.