Here's a geology project that uses historical seismograph data that you can collect from the comfort of your own computer. You'll use a web interface to a network of seismometers run by the Northern California Earthquake Data Center, at the University of California, Berkeley. From the seismograms you make, you will be able to measure the time it took for the seismic waves to travel from the earthquake epicenter to the recording station in California. Once you measure the distance between the two points, you will be able to calculate the speed of the seismic waves.