For what it is worth, what you are refering to is a session ID which uniquely identifies you for some period of time until you log out or the session expires. What I am refering to is different, it actually appears to be an encoded password. For example after clearing my cookies, using the encoded password I mentioned I can go to...

http://empeg.comms.net/cgi-bin/wwwthreads.pl?Username=mcomb&Password=jibberish

and go to the main index page and be logged in for that page (it says welcome mcomb and so on). That encoded password stays the same between session and does not expire for serveral years. Of couse as soon as I click on something the username and password are no longer contained on the query string so I am essentially logged out.

-Mike