Hi!
Sony's policy of not selling books outside the US is quite strange. You can buy ebooks from fictionwise, mobipocket or ereader from anywhere.
Given that publishers target is selling books (the more the better) I suppose that Sony's restriction is self imposed, for some reason.
I can only remember one ebook where I found some restriction. A couple of years ago I tried to buy "The Da Vinci Code" in ereader.com. The web replied that, due to restrictions from the publisher, this ebook could only be sold to customers from US and Canada. The system checked the personal profile stored in the system to allow the customer buying the book. So, I "moved" to Canada for ten minutes
L.