I have written before about the genealogy wiki called WeRelate.org. WeRelate's stated goal is to "make it easy for you to discover and share information about your ancestors." I am enthused about this great service and I wrote an in-depth review of the service about a year ago. You can read my article at http://blog.eogn.com/eastmans_online_genealogy/2006/06/werelate.html.
RootsTelevision now has added a video that describes this service in detail. The video walks you through the use of the service step-by-step. You can view the video if you click here.