Marware Sidewinder for iPhone
I love the Sidewinder for the iPod, because it has built-in headset organization. The Sidewinder for the iPhone has the exact same thing, and so far it's got my vote as the case to beat. I love combining things like a case and something to take care of those pesky cords.
bought it and the holder broker after only 2 weeks of usage. it made the iphone slip over the pavement which means it's scratched now :-(( The edges are not protected anyway. Don't buy
This is a bit like the Sidewinder from the same company, but it takes the cords and headset and sticks 'em on the back rather than the side, meaning it's still narrow enough to go in your favorite pair of skinny jeans.