If you are walking across someone's path (i.e. you are walking along, and someone else is walking towards you from a 90 degree angle), the correct thing to do is to either keep the same pace, or walk faster. Under no circumstances are you to slow down or stop.

If you keep walking, the person walking towards you can adjust his pace slightly, and aim just behind where you are likely to be when he reaches you. By the time he reaches you, you will no longer be in that space. If, in the meantime, you walk a little faster, you'll ensure he misses you by more. This is an approach you really can't go wrong with, and it requires the least effort on the part of both parties.

If you slow down, he will have to readjust to react to your new speed, and go further out of his way to walk around you. This is annoying.

If you stop entirely, you'll end up with him walking straight at you, and you'll be left in that stupid "do I go left or right" dance that people end up in when they meet face to face. This is even more annoying.

This public service announcement was brought to you care of some stupid git on Erskineville road.