Be a Martian
Do you want to help NASA crunch data. The Be a Martian website gives you a chance to do so. NASA is calling for help. They have so much data on Mars they cannot processes it all. So you can sign up and start helping right away. At the website, you can align parts of maps to see if they correspond to the rest of the map. Or you can count craters. All you have to do is sign up with NASA to be a volunteer.
All of this earns you reputation points. The reputation points help the scientists keep track of who has been helpful. If you only have 100 reputation points, then the scientists will not come to you to ask for more help. But if you have 10,000 reputation points then the scientists know that you have actively contributing. You get 100 reputation points for mapping or counting craters.
There is also a polling place, where you can vote on questions that you think or don't think should be answered. You can also pose questions of your own concerning mars, and see if you get an answer. Most of the questions are answered by scientists with links to where you can get more information on the subject.