I'll advice you take a look at the custom user models documentation. It is new in django 1.5 which will become the latest stable version in less than 2 weeks from now(?). It looks like the cleanest way imho. Sorry I don't have the link but am sure a simple search will lead you to the django doc page.
-------------------------- Sent from my mobile device -- You received this message because you are subscribed to the Google Groups "Django users" group. To post to this group, send email to django-users@googlegroups.com. To unsubscribe from this group, send email to django-users+unsubscr...@googlegroups.com. For more options, visit this group at http://groups.google.com/group/django-users?hl=en.