Auth:: Persistent authentification

Hello, I am using Auth:: and I think it is quite good but I also think it lacks a feature. Currently it only handles authentification for a session. It is very unhandy for my purposes because my visitors have to authentify each time they come to my site. I would like to implement a cookie based authentification in order to avoid this. I have seen no way to do it in the current version of Auth:: so I am planning to add it by myself but first I would like to know if this feature had already been added by someone and what you people on list newsgroup think of it. I would like to add a duration (in days) for the cookie in the login part. A value of 0 would mean "only for this session". Regards Jean-Marc