This suite of applets and associated research are phenominal. I have been using them in my general physics courses for more than 4 years.
You can use the apps in what I call "experimental" mode to try to generate some data and allow students to do their own.
Technical Remarks:
You probably want to download the java applets to avoid difficulties over a slow network, and then have to make sure your computers are setup properly, but once that is done, it is smooth sailing.
