Anyone have a recommendation for a UPS that can talk to my NetBSD/mac68k
   via the serial port?  I've heard some UPS makers will provide the info to
   talk to the UPS while others keep it proprietary.

I have some Best Fortress UPSes that seem to work great and will
communicate via an available protocol.  Unfortunately, I've only
messed about a bit with communicating, but it worked just as claimed.
It would be a relatively simple job to write a daemon to monitor the
UPS.

I like these because the communication protocol is available!

Cheers,
Brook