I have attempted to pick back up our disscussion on uservars by defining a 'light' and 'full' API both of which the uservars_pages plugin implements. The light API could be implemented with sessions or cookies, but the full API is needed for user management. Once this stabilizes I'll revise my plugins to use the 'light' api wherever possible. Please take a look at how this looks: http://erfurtwiki.sourceforge.net/?id=SessionVariablesAPI