There are a few apps that are great demos for the iPhone. Pulse News is a super RSS feed reader, iMovie always drops a few jaws, and Siri is a pretty amazing way to talk to your iPhone and get intelligent search results.
You can add Prizmo to the list of great demo apps, and it's going to be a very useful app for a lot of people. Prizmo combines OCR (Optical Character Recognition), text to speech, and translation
