Tim Perdue had an article http://www.phpbuilder.com/columns/tim20000505.php3 on a login system for websites, at the time I wrote comments that his login protocol can be spoofed easily and said I'll write an article on the topic, I've finally did and it can be found at http://baruch.ev-en.org/writings/
I'm writing this as a message here instead of a reply to the article since it seems like article replies are not being approved lately.