Everyone is so excited about tethering the iPad 2 to a projector, admittedly very cool, that we have missed something else at least as good if not even better! Go all the way: make the iPad 1 or 2 into a complete interactive whiteboard solution!
What a simple tool!
Add six "terms"and it makes a net for you (dice maker basically) great for language games, new terms in a UOI or anything that you might think of (how about as an instead of "then"cube