You are forgetting the BEST 3G network in the UK.
80% coverage and always increasing, best 3G phones, best expertise, been going the longest and approprately named!
I am planning on buying one from O2, unlock it asap and then bung in a 3 sim card and happily vid call from there.
I'll be honest.
Currently, the other networks which have 3G services, Orange, Vody, T-mob and o2 are rubbish at it.
Vody have the second best coverage (about 40%) but they have seemless connections between 2.5g and 3g unlike 3 who's 2.5g service is provided by O2.
And in case you didn't know... O2 have the worst 3G coverage in the UK, they started too late and know if they don't have 80% by 2008 (i think), I am not sure whether they will loose their 3G operating license. They current;y have around 12%.
For more info on 3g go to www.3g.co.uk
Current: HTC HD2, WP7 8779, HD2O ROM
Retired:HTC Blueangel OS: 5.2.2000, PDAViet ROM