I've just bought myself an iphone after switching from vodafone to O2, and in general i'm really happy with it, but......I don't know if it's the O2 network or the iphone itself, but the first thing I noticed is that the call quality was pretty poor. Not so much the loudness, it just sounds like the caller has an echo/talking through a rolled up tube. I can make out what they are saying, but it is definitley not crystal like almost every phone I've had previously. I was just wondering whether it's the O2 network, the iphone in general, or my individual iphone itself??. Could anyone help out with their experiences of their own call quality on the iphone?? Thanks.