I've beed asked about an easy to use, multi-platform (windows and mac), multi-machine mailing list and address book management solution that is free or cheap. Does anyone have anything I should read up on? I'm kind of getting scared that I think that openldap in conjuction with some mailing list software might still be the best thing for this. It would be ideal if it was easy to make sub-lists. I love the way gmail's contacts list works, but they're explicity that the gmail accounts should be for personal use only and not for groups. Google groups stops having the nice contact organizaion.