Theatre of Science!
Website here. It doesn't really seem to give a good description of their show (not that I've seen it), but from what I've heard, it's amazing. During the show, they cover all kinds of science topics, one of the things that they do, is they have a contortionist on stage performing, while showing scans of her doing her routine taken in an MRI! They end the show, with one of the scientists getting into a metal coffin in the center of the stage while two giant Tesla coils (one at either end of the stage) send millions of volts rocketing across the stage!
Sadly, the only US show I know of has passed, but they do have a sign up form on the website to be notified of future dates.
You can download and listen to an interview with one of the members of Theatre of Science here. The guy says that after the show tons of people come up to him and say that they wish science was taught that way in school as they'd have gone into the sciences then. The guy's an ex-magician and uses magic tricks in his performances (he then breaks the tricks down and shows you how their done, while giving you a science lesson).
How the idea came about is that he happened to mention one time at a lecture that in the past there used to be a great number of science expos that drew large crowds. A promoter happened to hear the talk and said that he'd like to put on such a show, the guy said that he'd be happy to do it, but he didn't think that they'd get many people willing to show up. Every show has sold out well in advance.