Basically Mailing list, now this could be done by creating groups and putting the email address you want in them so then when you go to fill out the alert condition you just variable to the group name for that list of people. But the way that might be even better is to allow us to group users how ever we please and add a email address field to every user profile, so then you can just variable to their username or to a whole group depending on what you need.
My apologies for any grammar atrocities in this post.
