I keep my heels about shoulder width apart. That way I am able to sit back into the hole. Get Rippetoe's book and do the squat stretch (elbows between your knees and hands together) this is proper foot placement for the squat. Doing squats this way will strengthen the glutes and hams (as well as the quads). BTB is right about Louie and others though. They're suited and hepped up on gear. Still you should be able to build up a very respectable natural squat with a comfortably wide stance. Nothing too dramatic, just give your ever expanding ass enough room to get down between your heels.
Bogdan Petia Sarac - Must keel moose and squirrel
Cancer Survivor - 7/21/10
Benchmark 5K time: 27:45 (3/5/11)
It's not the weight we move, but the people we move that matters. -- Bearded Beast of Duloc (12/31/10)