The Maryland Association for Justice has a fantastic listserv. I recommend it for anyone who is handling personal injury cases in Maryland.
On any listserv, there is invariably bickering over what is appropriate on the listserv. What follows an arguably inappropriate post is scores of emails offering opinions, jokes, and the rules of the listserv. It is as inevitable as death, taxes, and more Tiger Woods bimbos coming forward.
Above the Law has a great post on the University of Maryland law students dealing with the problem of unnecessary listserv posts.