Hi, I'll be in the UK for 2 weeks, and want to take my US/ATT iphone 3g with me. I'd like to have data service, for use with maps, etc. I would like to get the o2 pay-as-you-go SIM card, favourite place, with unlimited data bolt-on, for a £10 top-up. I see people selling these on ebay for £30 or more, plus shipping to US, which seems outrageous to me. My question is, can I just walk into an o2 store or supermarket and buy one of these sim cards, or will it be hard to find in London? Should I buy one on ebay so I have it before I leave? Will o2 sell one to me without any hassle about my (soon-to-be) jailbroken and unlocked US/ATT iphone? I haven't traveled internationally since owning a mobile phone that works overseas, so I'm a total newb to all this. Thanks!