Any good summer electrical projects?

[Zholl]

I was just wondering if anyone had any good electrical projects that I (or anyone else interested) could do now that school's out for the summer. I'm currently looking to get parts to build a Mintyboost, but after that I'm not sure what I should play with. I'd really like to get my hands dirty now that I've got some free time. if it helps at all, I already have a basic knowledge of electrical circuits, though I'm a little fuzzy fuzzy on capacitors and haven't gotten into logic gates, and I know how to solder and all that good stuff. I just haven't been able to find any projects here on CD while I was digging around.

so to all you more experienced electrical types, what kind of electrical projects or learning resources can you recommend to a high school student like myself?