Originally I though I'll just take a screenshot of my app on the iPhone then tweak it in Photoshop.
The images should be 480 x 320 according to Apple doc, and the dimensions of my screenshot are 480 x 320. But, the screenshot contains notification area (where reception bars, battery life, etc. are displayed)
So, if I chop that part off my image will be a bit shorter and not 480px high.
What do I do? Submit a shorter image? Stretch it up so it's 480px but without the notification bar? Submit it with the notification bar in the image?
How did you create your Default.png?