It doesn't matter because I just called Best Buy at Lakeside and they told me they don't sell the phone officially unlocked by itself. They only do O2, Vodafone and Orange contracts.
As I mentioned in another thread, there is no shortage of iPhones in London, if you are happy to pick up a contract. Both my cousins (one on O2 and one on Orange) were able to just walk into 2 different stores, renew their contracts and walk out the door with their new iPhones. It's the official SIM unlocked phones that nobody can get.