I did a google - try the following:
http://www.myus.com/
http://www.myusabox.com/
http://www.shipito.com/
I have not used them, but was seriously going to try the first one (myus.com) to get a Sony, then the BeBook was released and was a much better option. They also offer US credit card service, where they use their US cards to buy stuff and they bill to your foreign card.
There are a lot of retailers that won't ship outside US - I have managed to find alternatives for what I need, but have kept these handy just in case.