With the NDA finally lifted, it's time for my first quick iPhone SDK article.
Recently, I developed an iPhone application for a company a friend of mine works for. The application worked well, but when the application was complete, the one thing missing was the icon in iTunes for the application. Whenever I built the application and imported it into iTunes, instead of the proper application icon, which I had properly defined, I kept getting a plain black icon with an 'A' shape in it - In other words it kind of looks like the Interface Builder icon, but in monocrome on a black background. I tried everything I could think of to fix this. I searched all the iPhone SDK documentation. I found references to a 512x512 image you had to create for the app for this, but there was no information that I could find as to WHERE to put it. Finally, in frustration, I emailed another iPhone SDK developer who already had a published iPhone application and asked him how to do it. He responded back and gave me the solution.
In short, create a JPEG image named 'iTunesArtwork' without any file extension. Put it in your project so it's in the Resources folder. When the application is build, this file will end up in the root directory of your *.app package. It is this file that iTunes looks for to display as the application icon in iTunes. I believe the icon really should be 512x512 pixels, for best appearance, but a smaller icon will work.
I hope this helps someone get past this seemingly undocumented requirement. Good Luck