Steve McIntyre has set up a proper mailing list at unity@einval.com. This is the preferred way to contact the group as a whole.
To subscribe etc., visit http://lists.einval.com/cgi-bin/mailman/listinfo/unity/
Here's the previous address list, just in case:
Steve McIntyre <steve@einval.com>, Vivek <vivek@etla.org>, Alden Spiess <alden@einval.com>, Ben Chalmers <ben@solipsistworker.org.uk>, Tristan Barback <tristanb@ntlworld.com>, Mike Pitt <mikepitt@coriolis.greenend.org.uk>, Simon Booth <sgb@cantab.net>, Catherine Pitt <cneal@chiark.greenend.org.uk>, Steven Kitson <skitson@greenend.org.uk>, Rob Hague <rob@rho.org.uk>
And here's a mailto: link in case you've got your browser set up to do something useful with those:
mailto:steve@einval.com,vivek@etla.org,alden@einval.com,ben@solipsistworker.org.uk,tristanb@ntlworld.com,mikepitt@coriolis.greenend.org.uk,sgb@cantab.net,cneal@chiark.greenend.org.uk,skitson@greenend.org.uk,rob@rho.org.uk
(In either case, you probably want to remove your own name before hitting "send")