A little while ago I mentioned in a post on the PHP-General mailing list that I'd implemented a way to persist data between page requests without requiring server-side storage. This raised a number of questions which I answered without giving too much away.
A few weeks later Jochem Maas asked for a more detailed explanation. I had already started writing an article for this site explaining the details but since it's a low priority I hadn't finished it yet. I have now.
Sessionless Sessions is a somewhat confusing title but I hope I've explained what I mean clearly within the article As always comments are welcome.