We know of a few iPhone applications that were unloved by Apple. What are we talking about? You know ... the cool iPhone applications that developers make -- then Apple doesn't approve of them, and they never see the light of day again (or maybe they do). Needless to say, there are probably more iPhone applications out there that we don't know about.
That is the basis of the iPhone Application Graveyard -- it is a website designed to document all of the rejected iPhone applications. The site is run by Peter Hosey of Growl and Adium fame. Developers can email him tidbits of information about their unloved application, and he will post it to the site.
Which rejected application do you wish you could have on the App Store?