O2 in the United Kingdom briefly began taking pre-orders for the iPhone 3G on its website this morning, before stopping the sales minutes after they began. Customers who pre-registered their interest in the new handset through O2’s website were told this morning that the iPhone 3G was available for pre-order online, only to be referred to a customer service line after filling out a form. The Register reports that reader Carol Dew called the number, “only to be advised that they couldn’t take telephone orders until Friday, and they were very sorry for the inconvenience, but they had 2000 other people just like me calling them this morning, and their managers had advised them that the site was overwhelmed. Because they didn’t anticipate the demand. But when I asked how many iPhones were in stock, since I was afraid they’d run out before I could order mine, I was told that they’d asked customers to ‘register their interest’ on the website (did that; hence getting the text this morning). And that every time someone registered their interest, they ordered in an iPhone for them. Yet they didn’t anticipate today’s demand.” Interestingly, O2’s pre-order announcement indicated that orders would be delivered by courier on July 11, raising questions as to whether the handsets would have arrived unbricked and activated, or whether Apple has plans to allow at-home unbricking and activation in some countries.