I used my iPhone 4s and the app camera awesome (which is free & a cool app made by SmugMug) and processed them in the PhotoForge app, which works a lot like photoshop. To obtain a stable image and avoid camera shake, I used my headphones as a cable release and pressed the + on the volume control to take the shots. If you take your time to get the composition and focus nailed, you can get very good results from the 4s.
Todd
Todd