Maybe other phones do this too but this is the first one that i'v owned that did.
For those whose car has an auxiliary input and use your droid for music and such, i discovered a hands free feature. I use a window mount for the Droid. If you are listening to music while it is plugged into the auxiliary input and a call comes in, just answer it. Not only will the call come through all your speakers in your car, but the Droid must jack up the MIC sensitivity cause i can talk to whoever called me at my normal volume. So I can listen to all the music i want, navigate, whatever, if a call comes in, i can talk hands free to.
I have asked people that i am talking to how i sound, and most don't even know that my phone is like 2 feet away from my face. what's also cool is that if you take a call while navigating, you can go back to navigating while on the call. And if you don't switch back to the NAV screen, the NAV voice will still give voice prompts while on the phone.
Easily the best phone i've ever owned.