I am pitching an iPhone app, pursuing my dream of having my own company. A superb tech from an outsourcer I use recommended me the mockapp.com powerpresentation templates for making quick demos, or even a mockup. Playing around with it right now, but it looks nice and a very nice free contribution.
The mockapp concept is that of tweetware, you have to tweet, blog, or email 3 friends about it, if you use it. That is a pretty smart marketing concept, and hereby done. Actually it's probably "just" a commons attribution license, but tweetapp is more hypeable  I guess.