You can get some huge voltages from a simple Van De Graaff generator and still be fairly safe. You can spin one up with any small motor, like something out of one of those $10 table fans. I made one many years ago and the big problem then was finding a suitable belt. (at IBM it was easy to come up with junk motors) I ended up buying the belt from Edmund or one of those other mail order "science" places. The "ball" was an old metal globe that I buffed all the paint off of. I imagine now days with the internet, parts are easier to find.
