An OpenSource Solution to Yahoo Groups?
As you may know, I've been working for quite some time on putting together some sites using open source technologies. I started this site on Mambo, moved it Joomla, and am now using Gallery, extCal, and some others to make everything work. I've also got a couple of other sites going, including www.friendsofaclc.com and a site for Loren's Ultimate Frisbee team, which is a major work in progress and isn't quite presentable yet. (if you really want to see it - it's currently at www.jenndiesi.com/darkmeatultimate.)
Anyway - one of the biggest missing pieces with all this is the functionality that Yahoo groups offer. You see, the ultimate kids and parents use a Yahoo group to do the bulk of their communications, and they need to keep that functionality. You'd think that with as popular as Yahoo groups are, that someone would have already been all over this technology and have something similar developed - but that hasn't been the case. In fact, it's just been in the past six months or so that someone has taken on the project, and it's nearing completion!
Now, I'm not complaining. After all - all of this wonderful technology comes relatively freely to me; and I don't have any free time to work on these tools myself. (though I'd like to get involved, as soon as my schedule frees up!) In the mean time, I'll just have to be patient, and wait for the good graces of more time resourceful programmers to deliver the goods. 
http://www.simplemachines.org/community/index.php?topic=40848.0