Just signed upto the London Devops mailing list, and thought I'd just point out that one does not need a google account to join a google groups hosted list. Just send an email to the <list-name>+subscribe@googlegroups.com with 'subscribe' in the subject line of the email, and their list managment software will sign you up.

So in this case, sending an email with:

To: london-devops+subscribe@googlegroups.com
Subject: Subscribe

.. would be all thats needed to get you on there.

Google groups has a help page with details on what all services they host which dont need a google account to use.