Bruce,

Sounds like some good work.

With all the lightning strikes you've reported, it sounds like you might be in Florida - they're the lightning capital of the USA.

DalSemi has some ESD protection components made for the iButton that I use. You might find interesting:

http://www.dalsemi.com/datasheets/pdfs/9502.pdf
http://www.dalsemi.com/datasheets/pdfs/9503.pdf

The bad news is that its only SMT packaged. If you don't have a Metcal soldering system, hand soldering SMT can be a challenge.

I like a DS1820 equivalent with the same or better accuracy in a I2C interface.

-Jay C. Box