Gem, that was incredibly useful information. My application is a multipage form- (over many pages, probably 150 fields of information collected per form). The issue that you bring up that is most troublesome is IP tracking of more than one user behind a NAT router. The others are less an issue for us--though we do use embedded Flash, but do not post or get from or to those applications. We keep Javascript to an absolute minimum for other reasons. So far the Zope CookielessSession product has worked flawlessly for such an application, but I'm not sure we have encountered multiple users behind a NAT router, though that would seem a common occurence. Much as i dislike using cookies, perhaps I should reconsider them. Thanks! Harlow Pinson Indepth Learning Email: hpinson@indepthl.com Web: http://www.indepthl.com Voice: 505-994-2135 FAX: 208-475-7678