that can remove the more minor dents w/o the need to repaint. In the old days, they use to use dry ice. I think most have some other procedure they use now, but it's basically the same end result.
I'd just recommend either looking in the Yellow Pages under Automobile Repair or whatever would be similar, and you can also contact the Service Dept of your local dealer. Since it sounds like most dealers outsource this type of work, they should probably be able to give you a name or two in your area.