Pan Left Productions

The link below discusses one the first music videos to be shot entirely on an iPhone. I don't think I would use an iPhone for that, but its an interesting experiment and I think it looks pretty cool. My guess is that there were some image tweeking done in post. I like it.
If you spent $300 or $400 on an iPhone and you then realize you could have used that money toward a nice HDV camera, this is a good option. I don't think it would be a good option for a narrative with sound unless you recorded the sound on a different device.