I never play world map anymore (I find that knowing where all the land is already is too boring, since I like the discovery phase of the game), but when I DID, I found that if I selected the Americans, nine times out of ten I'd have to deal with either the Sioux or the Aztecs (often both)--I think the computer tries to ensure that you'll be sharing a big continent with SOMEONE....
Which is why, if I'm in the mood to not be disturbed in early game (and I usually am), I choose archipelago on a big map--there's about an even chance you'll have your first island to yourself (especially if it's a small-to-medium landmass)--or if you don't, you'll be separated by an isthmus (chokepoint) which you can easily defend from....
[This message has been edited by allan (edited August 30, 2001).]