Not a faction, but I am currently working on organising the few members of the OnRPG.com forum community who are playing FO:R. I've set up a shelter near NCR to act as a sort of base until (or if) we decide to upgrade to an actual faction base. Probably wont, though. But if you want to work together towards goals and such, you can join me in the #onrpg irc channel hosted on the same network as the FO:R irc channel. I can hook you up with access to the Shelter and then we can make plans from there.