Thought i'd add this guide with reference to the Apple I Touch i bought one from the USA (brand new) the guy took ages to send it, anyway as it was on it's way the guy said he couldn't access i tunes on his pc with the I Touch.

What he failed to tell me was the I Touch was locked and this was the reason why.

anyway one quick call to Apple UK  i gave them the serial number off the back of the I Touch and confirmed it was from the USA this however isn't a drama as it's not the I Phone and Apple had changed the registration into my name to give me full warranty and sorted out my problem with the I Touch being locked there and then on the phone by way of a hard reset and reinstall of the software from i tunes.

So all i can say is buy the I Touch from the USA with confidence just phone Apple to get the serial number of the product in your name and the warranty.  I have to mention too that Apple UK helpline were extremley helpfull.

Sellers from the US will pretty much  fail to tell you to register your product with Apple UK.