I know this is an old thread, but i thought i'd throw in my $0.02.
I have a mogul, and i got a bracketron brand mount from Best Buy for $20 bucks. It's the vent mounted variety. It actually works really well in my car (bmw e36.) I have it set to hold my mogul horizontally, w/ the top slid up and keyboard exposed.
It works really well in my car because of the position/design of the vent. It places the phone up high and up off the dash, so it's so close to the steering wheel that i can actually navigate menus w/ out having to remove my hand from the wheel.
Works great for GPS navigation, and for general one handed use.
Here's a couple pics to give you an idea of how i've get it set up in my car.
