apartment therapy changing the world, one room at a time

I don't think its as simple as this. A little experimentation may provide the opposite advice depending on ceiling height.
http://www.wonderquest.com/Fans.htm

The ceiling in my loft is 17.5 feet away. All of the hot air is at the top.

In a typical room, when the fan is blowing down, the air hits the floor, heads toward the walls, heads back up against the walls, across the ceiling toward the fan, and back through the fan. Vice versa for the opposite direction.

So, either way you are just mixing the air. In SeanG's loft, the fan is either going to be pulling the hot air through the middle of the room (forward) or pushing the hot air down the walls of the room (reverse). The 'correct' setting may depend on where you are sitting.

Now, the stairwell situation in SeanG's link gets really complicated, depending on how the HVAC system is set-up, whether or not it is running at the time, etc.

Just FYI, some ceiling fans (like mine) don't have a switch for this purpose; they have an extra cord instead.