Found this a few years ago and always end up showing people. It really does show the "quality" and "persistence" of wiki data in a way that begs the "ohhhhh, yeah" moment<p>and if anyone wants to contest the "valuable medium" bit, I'm thinking the wiki hasn't properly come of age yet - for instance see <a href="http://www.scholarpedia.org/" rel="nofollow">http://www.scholarpedia.org/</a>
I guess I just don't get why this would be "the only way to convince yourself that the "wiki" is a valuable medium". We use wikis at work without this, and I don't think anyone here would argue that it isn't a valuable resource. The history flow would show persistence of information, but for many sites I think it would be a stretch to claim that proves the quality of information.