hey dude I have the BTB200 but with the AVH-P4100DVD and i have the 1st gen iPhone and it works great. It shows the number on the screen when u get a call, u can answer/end calls and dial numbers to call. works great. U can also transfer contacts 2 the headunits memory but I dont think the iPhone has that capability yet. (maybe when the iPhone 3.0 software update comes, because u also be able to stream music via the bluetooth with that sofware update)
hope thats helped