Okay, this may sound crazy, but there's a logic.
I need to set up multiple instances of Drupal. Easy enough. Drupal makes that simple. HOWEVER, I also need the different sites to share the information. Before I continue I should explain the goal.
My website (www.dreamsfade.com) is for a small, independent record label. We want to manage all of our artist's webpages in a way that will easily let them update content about themselves. We would like for the sites to share a user database, so that users won't have to sign up for DreamsFade.com, Archangel.DreamsFade.com Ethos.DreamsFade.com et cetera, they simply sign up for DreamsFade.com and they are done. Another thing: we would also like for the sites to share articles with the main page. The idea is simple: each band will create news articles about themselves which will appear on their pages, however all of the artists' news will be combined to create a news section on the main DreamsFade.com page.
So I need to find a way to set up my main site to share it's user data with my sub-sites. I also need to make my sub-sites share their news articles with my main site. To top it all off, I need to create a page that will allow me (the admin) to select which users are our artists and hence get their own sub-site, and automatically create the files for that sub-site. Users that are not our artists should only be allowed to view pages, comment on things and participate in the forum.