Stuart sent this link to the messiest datacenter ever. It actually looks pretty organized considering that there aren’t proper racks or housings for the motherboards. I’ve seen worse.
Though I have no pictures, a server room I once managed only had one air conditioner and that too on one side of the room, near the door. We had to improvise a ventilation system based on powerful small fans and a duct made out of garbage bags to get rid of the heat.
On another note, I was up in the Margalla hills a few nights back with some friends and someone commented on how much Islamabad resembles a server/router room from up there. It really is an awesome sight since the city is a well-lit, almost geometrical grid of roads and buildings.