First off, for those of you who don't know what a wiki is, start off here, and then keep in mind that that site you're reading? It's probably one of the most successful wiki's around. In short, a wiki is a website that's open and editable by anyone (or, at minimum, any member) of the website. Think of it as a giant group blog.
Anyway, in short, what I'm looking for is a wiki that could active as a living repository of all things knitting: Techniques, tips and tricks, stitch patterns, information about materials, different knitting styles, etc, etc. Basically, a free, live, open knitting book that could be edited and contributed to by any member of the site, where we could all deposit the various knitting tidbits we've collected.