Check this out for those of you that don't want to install or buy cables. It connects to your phone via bluetooth and then connects to your radio via FM and you can take calls through your stereo and play music off the phone. I haven't tried it yet but seams it would meet many needs here except charging so you would need a cable for that.
http://www.fommy.com/view-full-page.asp?divid=T-Mobile&cat=Bluetooth+Car+Kits&skuno=80842