This is so f***ing messed up... it seems Apple has just started using IPs to close off the US app store to the rest of the world.
For one thing, at the moment the app store app on the pad just quits, it does not even redirect me to the UK store.
But that's the least of it. I have bought tons of stuff in the US store, and it seems some of it I can't use now.
It gets worse: some of it, for god knows what reason, is not even available in the UK app store. I can't even pay again for Instapaper there, and get a working version!
Instapaper was my favorite app, what am I gonna do!
... Also, at the moment, Instapaper is incapacitated, it is stuck in the middle of an update, which it seems it can't complete since the app store suddenly closed. I'm very irritated.
Update: I also went through the various update procedures in the iTunes app on the Mac, and this may actually have done the trick! It seems Instapaper is updated. I hope it keeps.