I had posted an earlier question regarding using FIM to provide a delegated adminsitration portal (add/modify/delete users - not just group membership) on the internet and was informed that it would not work - FIM was designed (tested) for internal use only. I have a slight variation to this, what if FIM was fronted by TMG and authenticated extranet users were given access to it. The other factor is that the extranet users are in a different domain than the internal users. Is this scenario supported? Thanks, BillBill

Supported? No. Will it work, quite probably. As far as I'm aware there's no external access options available in a supported manner other than using Terminal Services and/or Citrix. If you want to manage an extranet then you will need to synchronise the extranest AD users into the FIM Service.