Making an iPhone icon is way easier than I had anticipated. You don't need to round the corners, you don't have to give it the little glow as if the sun is shining down upon it. Simply make your icon in a 57x57 png and the iPhone SDK does the rest for you. Here is a
link to some good apple
documentation on making an iPhone Icon. See the icon I created below (1) and the icon that showed up once I plugged the image into xcode (2).
1. 2.