"beat the system" tip #26: which side to walk in the concourse
In the US, people walk on the right. In Australia, on the left. In England they walk all over the place, saying "Sorry," to each other.
Except in England, there is usually a discernible flow which, if you follow it, will significantly cut down on your head-on collisions.
(from The airline Passenger's Guerilla Handbook, ISBN 0-924022-04-3)