This plugin allows you to write e.g. shopping cart code which should behave well for guests as well as permanent users. The basic idea is both logged in and not logged in users can get the same benefits from sessions where it doesn't matter, but that logged in users can keep their sessions accross logins, and will even get the data they added/changed assimilated to their permanent account if they made the changes as guests and then logged in. This is probably most useful for e-commerce sites, where the shopping cart is typically used before login, and should be equally accessible to both guests and logged in users. WWW: http://search.cpan.org/dist/Catalyst-Plugin-Session-PerUser/