I see all your authors listed on the U.S. Amazon Kindle Store site (Discworld only has 4 titles, so it's a case of not every book being in ebook form).
There are those who have changed their address to
Disneyland or some such location and are buying content from the U.S. store. If you go this route you may want to set up a separate Amazon account just for your Kindle with the U.S. address, register your Kindle to that account and fund it with Gift Certificates/Cards.