Multiple BSP Teleporting

But then what about dedicated servers, where there IS no host? How does the dedi determine which BSP to use?

This sounds interesting. I might experiment with this a bit.

jahrain made up a script that did bsp changes in a mp map to change the time of day.

A dedi is just a host w/o a player. It still runs the map.
I used BSP switches on my map, it requires some scripting and stuff, but it works.