Very brand-conscious start time aside, looks like UK customers on O2 now know what time the queue ends and the buying begins...
UPDATE: Sounds like the second poster, below, might be there just in case a store sells out and wants to inform customers. Thanks to everyone in the comments for logic-ing this out!
Due to high demand we have run out of the iPhone 3G S
The good news is there are more coming soon
Ask a member of staff for details
Posterized version after the break!