I have to check and see if Aimoo is free or not....it's about the best I've found to date. Easy as pie to get around in...it's forum style.
Multiply would be my second choice..Ning is just too hard to figure out...I'm still wandering around lost in there. Yuka...if you start a group there, it is there for eternity..and is very limited. You can't delete a group there..and it's limited as to what you can do.
I wish msn hadn't done this to us....