Thorben Jensen has been generating some traffic on the Asterisk-biz mailing list over the last couple of days. He has announced a free virtual PBX service, called EasyPABX. You can head over to his site, sign up, get a free DID (in Denmark), set up some extensions, and you’re running. If you would like to use DIDs in your home area code, no problem, you can just point them at EasyPABX rather than use the supplied Danish numbers.
Met with skepticism on the mailing list, his explanation was "many things today are free", and he compared his business to GMail, or Hotmail. The voip-info wiki reveals that his business model is to court resellers who will brand the site to themselves, and provide their own SIP DIDs.