Keef;
You ask why I think the O2 tie up is crap?
Well, as someone who totally relies on his phone around he Country, I cannot be with a provider with such rubbish coverage outside of London.
Try using O2 in Scotland or Wales anywhere but a major city and you are stuffed!
I would Love an iphone, I even bought a pay as you go o2 sim to see if they had become any better,but...sadly no.
Without doubt Vodafone gives best international/regional coverage.
I'm not a Vodafone out and out fan, but it works...everywhere!