While this could be resolved easily with the iPhone audio port adapters from Belkin and Griffin that have emerged since the launch, I've been able to successfully play audio by connecting a pair of PC speakers to the audio out of the included iPhone dock. I tried this in my car as well and it works fine. I have a cassette adapter and an iPod charger from Belkin plugged into the dock. Now, I'm just waiting for an iPod cup holder to come in so that I can hide all those wires and keep my new iPhone from bouncing around the floor pans. The hitch, of course, is your case which limits your options.