I just purchased an 8GB iPhone...
I am trying to get it activated - apparently my existing Cingular account is a business account and Itunes says it can not activate the iphone for a business account.
So, things I noticed:
1) It's not as wide as my dash by a tad, but it's taller by a tad then my dash, and is thinner then the dash.
2) The SIM card from the iPhone does seems to work fine in my Dash.
3) I heard the sales rep say that the iphone can't read any SIM phone numbers - you will have to re-add all your contacts into the iphone.
4) The iphone doesn't see to be able to record video.
5) I thought I read somewhere that the iphone does support AD2P bluetooth audio, but earlier in this thread is says it can't. When I can get my iphone activated, I will try to use my Motorola S9 bluetooth stereo headset with it.
6) The iphone comes with a docking pad and a USB charger/sync cable, and it comes with an AC adpater that has a USB on it - so you don't need an extra AC adapter (which the sale rep might try to talk you into).
7) The battery is sealed, so I wonder when and how it can be replaced when it starts to not take a charge.
You definetely want to get the 8GB unit like I did...$100 extra to double the memory is a non-brainer - especially since it seems there is no memory slot to expand it.