Car Bean Bag Dash & Windshield Holder for the Apple iPod touch - Gomadic Brand
I purchased this mount for my iPod Touch primarily because here in California it's illegal to mount anything to the windshield.      This is basically a heavy duty bean bag with a metal plate attached to it.  The bracket and arm attaches to this metal plate with a suction cup (and can therefore be directly attached to the windshield itself without using the bean bag if need be).  The brackets that hold the iPod are heavily padded and grip tightly and securely, and also allow for easy attach and release.    