A friend who uses one of the most expensive apps I've seen (iBird: $30) sent me a photo of his new iPhone 3Gs. He had to protect his investment, of course, so he ordered a new skin from SkinIt.
On this site you select your device (in addition to phones, they offer skins for laptops and more) and then pick the image you want. There are many pre-designed images for $14.95, but my friend Mike created his custom skin by uploading a photo.
With the SkinIt customizer you can resize and reposition your image, front and back. The company claims it offers the strongest skin on the market.
Why Moe? Mike says, "It's a good fit, because like Moe, my iPhone always tells me what to do, wakes me up, etc." But does your iMoe pull your nose then conk you on the head, Mike?
You might consider creating your own custom skin -- just to make that iPhone different.
Here's a shot of the Customizer at work on an image from John Lennon's Imagine. Pay attention to the color of your iPhone, and whether the image will stand out against the black version, for instance. That's why the black-and-white Moe was a brilliant choice.
You can position images on both the front and back. Try to place the image that's on the front so the essential elements land on the top and bottom -- because the center is clear, of course.
Now, excuse me, but I have to go search for a good picture of Shemp...