I was in the same boat your in at one time, and I have the 860MP. The CDIB100II works really well with our head units actually, and even better with the iTouch and iPhone than with a regular iPod. I have an iTouch 16 gig model, and even while I'm playing music through the CDIB100II connection to my stereo, I still have full capabilities to do anything else on my iTouch. For instance, I needed to call a friend the other day, but his info was on my iTouch and not my phone. While driving I switched to the contacts and pulled up his number all while the music was playing. If I find a Wifi spot, the iTouch will still allow me to access the 'net, check email, weather, etc. All in all, the CDIB100II is pretty dang slick. If I can do all of this, I can only imagine that the iPhone would allow for calling people and probably even taking photos at the same time it is playing music. Thanks Pioneer for the CDIB100II, and thank you Apple for the wonderful iPods!
Dustin