I'm currently testing out Blackwell's (blackwells.co.uk) as an alternative to Book Depository. They at least deliver to me in Finland, although I'm not super impressed with their dispatch times. Order made on the 5th of April is still being processed.

Another alternative that I was told of, which I haven't tested yet, is Wordery (wordery.com). They advertise free worldwide shipping like Book Depository.