It's just like the name says - we shut up and write for an hour. You'd be surprised how much can get accomplished in setting aside one hour a week to write. The bonus is getting to know others with the same passion for writing. It works like this:
9:30- arrive, get coffee or whatever, and settle in
9:45 - introductions
10-11 - quiet writing time
All types of writers welcome - work on your novel, memoir, screenplay, emails etc.