I think it has something to do with your ISP, possibly the site checks where it's located and then loads the different country sites. When I tried downloading the html code of
www.google.com I got the code for
www.google.nl so I think the .com site is only redirects with the info they can get from your address. If I ask for my info on IRC I get something like 'some numbers (not my IP)@chello.nl' I think they use that to redirect