Here is a place to post some prefabs for level design that people may find useful. I'll start:
Name: Pipes
Description: Two pipes, about as wide as the Quake guy, one of which has a turn in it. It took me quite some time to get this to look right, so hopefully someone can get some more use out of it.
cool , i may make some. hmm question... is there a tool that converts .objs to a format like .bsp,. rmf, or .map ? if so i can push out some killer prefabes for you guys.