Hi all,
I finally put a page together on the California 150 passport stamp
locations. You may need to do a bit of research to find specific
ones. There are some that have very limited hours or that are only
open seasonally. Hopefully I can get some scans of the stamps posted
soon. The program officially ended in 2002 but I've been able to get
most of them anyway.

http://home.earthlink.net/~3vix/CA150/index.htm

Apparently the server is case sensitive so copy the link or type it
in carefully. I've also got a list of lighthouse stamps for the US
Lighthouse Society passport program. I think there are also a number
of letterboxes at these sites too.

Cheers,
3vix