I think that http://www.sfsi.org has been rumbling about doing a wiki for some time. Both for sex ed materials and sex info purposes coming from a non-judgmental but sex positive consensual perspective. I'll look into it and see if collaboration is possible with the organizers.

Update:   SFSI.org is in wiki format already (I hadn't visited since we switched over cough cough) take a look and see what you like, I know the programmers and the board of directors (I'm engaged to one of them) and could certainly forward or facilitate requests or introductions.