Why can't I buy apps etc from other countries with my itunes ID? Amazon lets you buy from its international stores without a problem, so I reckon it can't be that difficult to set up.

It's down to licensing - Apple are only granted licenses by the content providers (the film studios, book publishers, app developers, record companies etc) to sell their content in particular countries. If the providers are happy to have their content sold in each country then they will grant Apple a license for each country.

This has been around for a couple of years, a part of the problem, maybe the true basis, is as described by KP. Apple has since the inception of the iTunes and app store tied the user-store ability to purchase to the country and credit card of the user. The user must have a physical address tied to the credit card being used so that purchases end up only working in the country where the credit card is issued. And to make matters more difficult, I have not seen anything on here from users with credit cards issued in additional countries being able to make purchases from stores in those countries...the AppleID is tied to one account so you cannot setup accounts in multiple countries and then link them. While it may sound complicated, it just comes down to you can only buy from the stores in one country. For some of us who speak more than one language it is disappointing to not be able to buy books in other languages, but that is the system as it now exists.