The way I do it is as follows, I opened two accounts one with a US address the other with my address, from my addy I send a gift cert to the US account as all orders are ip checked I can't use my US account so I get my US friend to log in to my US account and purchase the ebook and he then adds it to my library. Done
Edit: Sorry, forgot to add that you need to get a Virtual Credit Card the one I use is Entropay.