Hm.. I can't say that I know of any cool aftermarket ones, however I can suggest getting the size of the clamp and going to Home Depot, Lowes, Ace or any other hardware store and picking up a new one. Perhaps the screw isn't so great and you can get a different type of (screw) clamp.
As for making it cool looking I am going to give, what I feel like is my answer for nearly every other question, is to just spray paint it
You can make it any color you want and always switch it up. While you are at the Hardware Store pick up a can. Check for ones for metal application. Rustoleum should work as should Krylon. The Krylon Plastics I believe includes metals.