Insanity Ball

Okay, the current idea, and hopefully what I actually end up making is this optical theremin and putting it inside one of the semitransparent large bouncy balls in my room, so that when it rolls it makes different noises. The photocells could be pointed at one side, so that when it rolls they face up toward light and then down in their shadow... it seems like the effect could be interesting.
That said, I still haven't got any of my parts yet! They need to show up.

So the project has changed! sort of. Back to closer to what it was going to be before.
It's going to be an optical theremin, but I'm going to do something crazy with it. Ideas for the something crazy right now include a clear pvc sword which changes what it sounds like when you wave it around, a really annoying mousepad, and an alarm clock that screams if you for using the snooze button. That last one might be hard because... it'd be screaming all night unless I figured out how to rig a timer up to it. I don't really know.

I like the sword idea, just because it'd be fun and I know I could probably get started on the non-electronic part at home over break, since my electronic parts haven't shown up yet.

what do?

SO, I think I'm making a theremin. Although... I have really pretty limited experience, and I don't really understand how they work. However, I know there are all kinds of kits and instructions and schematics floating around, if I can make sense of them. all else fails, I can probably fall back to some kind of fancier optical theremin, although I think I might be disappointed by that as a project.