Own Images in iOS Simulator

To add your own pictures to the simulator, get the simulator running and then drag your image onto the simulator. This will cause the simulator to open it mobile safari. Then mouse down and hold on the image, you will then see a prompt asking if you want to save the image.

http://www.flexicoder.com/blog/index.php/2010/06/getting-images-onto-the-iphone-simulator/