I stumbled across this article on accident this morning and thought I'd share it... for those who are new to SharePoint or need some clarification on authentication, user groups, user profiles, etc in MOSS 2007, check out this article on Bamboo's website... its quite well done and really helps make things much more black and white if you're unfamiliar with it.

http://store.bamboosolutions.com/kb/article.aspx?id=10829