http://gamespot.com/gamespot/stories...875039,00.html
That says that 3.9 million Xboxes were shipped by June 2002.
I can't find a link to how many Xboxes have been sold, but I've seen the breakdown before.
it's about 2.4 million in North America, 250 000 in Japan, about half a million in Europe, and a few tens of thousand (not sure how many, but I think it was about 39 000 or something) in Autralia.