Well there's an option in MovableType to do this very thing... I'm currently the only one subscribed to this, and I'm going to send this post to the blog and see what the email I get back looks like, if it's nice then it's easy to add people to it... if it's horrible then I shall do other more cunning things... ;-)
Bah! It only seems to do it if I tell it manually to send an update. Time for me to put on the cunning hat :-)