How much is too much session data?

Thanks everyone. I have decided that I will keep the session data as clear as possible, and everything else will be table driven.

I love the term 'fingerprint' from spjonez and will be giving that some thought. If the same finger print type can be used for anonymous and logged users, that would be highly beneficial.

I have really changed my mind on this so thank you again everyone.

Best wishes,

Paul.