One of the tasks for a new project I'm developing using Plone 2.5 is to enable visitors to login using their email address as the username. The project is developed using remember, membrane and b-org, so to enable this I have to change the way the remember members work.

One place on the web where this issue is debated was a recent discussion on the archetype-users mailing list.

In my case, I've simply override the validate_id using in my content type and made it use the regex validator described in the above thread.