Request for Tutorial: Using SSHKeyChain

Richard wrote about securing his email with SSHKeyChain in the context of pointing to Kees Cook's discovery of 45 clear auth POP accounts at OSCON.

I actually ran SSHKeyChain before my upgrade to Mac OS X Tiger, but never re-installed. It worked most of the time, but not all the time. To be honest, the whole process is somewhat hard. Richard (or anyone), I'm making a Request for Tutorial (RFT): please document both the requirements (what do I need in a mail server to support this?) and the steps involved in secure email.