Most of the dented wheels that come into my shop are accompanied by tires with only 15-20psi in 'em.
![Tongue](http://ducatimonsterforum.org/Smileys/classic/tongue.gif)
Hit a pothole with your tire underinflated, and voila! Dented rim!
There are shops that straighten rims, IIRC there was a recent thread, try the 'search' button.