This is the idea behind Yahoo's E-Groups. Some are by invitation only (especially when the members of the E-Group are the same as the members of an actual club). Others are open to the general public. Say you really enjoy photographing Saturn's rings from your backyard telescope and want to exchange email with fellow astrophotography buffs but the subject bores your friends and family to tears?!
Yahoo E-Groups currently has something like 68 E-Groups, some public & some private and some for particular cameras, etc., just for astrophotography! Groups are available on topics from hobbies to cooking to genealogy and a whole lot more. If you don't see one that interests you, you can also start your own!
Each group has a moderator (as do most message boards and Usenet topics). The moderator decides who gets to join a group, if it is a restricted group. Any member can send an email to all members of the group. If there is a lull, the moderator might send out a new message to "stir the pot", as it were. Or you can be a "lurker" (that is, just enjoy reading the email messages without feeling obligated to reply if you don't have anything to say right then).
No special effort is needed by the average member (unlike message boards where you have to go to their Web page and sign in). Just check your email, as usual, and email from your E-Group members is right there, next to the email from your Aunt Susie. To respond, just hit your Reply button and your reply is sent as email to all group members.
To join an E-Group, you need to establish a free Yahoo ID. Once you have a Yahoo ID, it's easy to join yet another group.
Most E-Groups also have a members-only home page within Yahoo E-Groups where members post photos, keep lists of favorite links, etc. Members can read the email while at this site or just read the email using their regular email (without going to Yahoo E-Groups first).
For more information see: