Advanced DIY Science for Students?

Adam Wise asks: "I'm a high school senior planning a career in science, and I don't have any plans for the summer. I'd like to put these two facts together to entertaining and educational results of the do-it-yourself variety. Reading about the home made electron microscope got me thinking along the lines of a similar project. Are there any resources specifically geared towards DIY scientists beyond baking soda and vinegar volcanoes?"