Thanks - that's a decent tip - I'm locked into my contract till April next year but can change in January because I've been with O2 for years but i may wait, see the contract out, then just buy the iPhone 5 and a cheap contract with someone as you suggest. Is GiffGaff about the best ? (I see it's owned by O2)
I've had no issues with it at all - decent O2 coverage and I often stream a lot of stuff over 3G - radio during the day at work, Netflix other times and it's always been fast with no indication that my bandwidth is being throttled. For a tenner a month it seems a no-brainer.