With that in mind, here are the 7 rules of prototyping put forward by Firefox creative lead:
1. Your first try will be wrong. Budget and design for it.
2. Aim to finish a usable artifact in a day. This helps you focus and scope.
3. You are making a touchable sketch. Do not fill in all the lines.
4. You are iterating your solution as well as your understanding of the problem.
5. Treat your code as throw-away, but be ready to refactor.
6. Borrow liberally
7. Tell a story with your prototype. It isn't just a set of features.
What's the reasonable time-frame of a usable artifact in theater creation?
If you've got time, here's the 30 minute video:
Rapid Prototyping with Aza Raskin from Dan Braghis on Vimeo.