NASA and Microsoft Corporation have created a website called "Be a Martian" (http://beamartian.jpl.nasa.gov/) where internet users can advance their knowledge of Mars, take part in research tasks, and assist Mars science teams analyze data. I spent some time on this site and found it very interesting. There are a couple of different things we can do to help out the scientists. Users can help create an accurate map of Mars by mapping high resolution images to the appropriate position on the Mars surface, or count craters. Since craters act as time stamps: in that older areas of the surface have more craters, by counting the number of craters in a given area can help determine the relative age of that area. Very clever!
I have also attached a link to NASA JPL's Mars Exploration website (http://mars.jpl.nasa.gov/).