A friend posed a question to me and I thought I'd share the step by step.

The question was: I'd like to create a twitter so that everyone in my group can send messages to everyone else by addressing it to the group.  Is this possible with twitter?

Well yes and no.  Twitter is group messaging system but it's designed to be a social tool meaning your 'group' will expand and shrink much like a circle of friends.  There's also no way to address messages to just certain people...unless you use http://grouptweet.com/

It's very simple!

1. Create a twitter account for your group - for our example, we'll create a group called BESTHOWFANS
2. Register this twitter account with http://grouptweet.com by typing in the twitter name and password for the group account.
3. Have all of the people you want to have messaging rights follow BESTSHOWFANS and likewise have the BESTSHOWFANS twitter account follow all of them back.
4. Whenever anyone in the group wants to send a message to members of the group, s/he simply sends a direct message to the BESTSHOWFANS twitter
   by typing "d bestshowfans blah blah blah' 
   It will then be distributed to everyone in the group via the grouptweet account.

It's very simple and it works! 

You can also set the BESTSHOWFANS to be a locked account so that messages don't appear in the public twitter timeline. 
If you do this, then the only additional step will be to accept each members request to follow BESTSHOWFANS twitter. 

I hope this is clear enough. Let me know if you try this and if it works for you!