You will find this discussed a lot on other forums, and it is a bit of a pet hate of mine, so I thought I would try and get a head start on here and hopefully nip it in the bud before it gets going.
You will find a 1000 threads saying "My iPhone wont work properly with Blue&Me!!!!!" That is because you are trying to get an Apple product to work with a Microsoft system. The two companies hate each other, won't work together, and probably even build them on purpose so they wont interact.
The plain truth is, an iPhone will pair with Blue&Me enabling you to answer calls. It will not copy the phonebook, give you voice dialling or read out text messages to you.
The Bluetooth on the iphone is not as advanced as the Bluetooth involved in Blue&Me, so anyone saying "come on Microsoft, sort it out!!" is yelling at the wrong company.
There is a full list of compatible phones available at
http://213.215.170.74/blue_and_me/tab_com.html. It breaks down which phones do what, but the phones on the list are quite old. A good rule of thumb, is that SonyEricsson phones are usually pretty good, and the Nokia's come a close second. Most new phones will pair, will only give you the answering feature.