Ooooooo-kay. Through some deduction and a lot of googling, I have determined the style of the CMUCam lens to my satisfaction. The camera board is a C3188 evaluation module for the OmniVision 1/3" OV7620 Sensor. As such, I think the actual mount on the board is the V-LH4-IR listed
here.
So the thread is M12x0.5 and any 1/3" format lens with a M12x0.5 thread should work just fine. This is apparently also known as an "S Mount" lens. For instance, the same folks predictably carry
several compatible lenses.
Here's a bunch more. Note that 1/2" lenses will work just as well, and you don't have to worry about the IR filter unless I'm wrong about the current mount having an integral one.
Also,
here and
here.
Personally, I'm intrigued by the variable focal length lenses, though they would obviously necessitate extra servos and such to really take advantage of them.