I suppose I'm sympathetic to some of the Sunstein-style arguments about the epistemic virtues of wikis and prediction markets, etc. (see Sunstein's Infotopia, if you're interested). But WikiHow seems to me to present highly compelling counter-considerations. WikiHow is an open source "how to" site, with entires on everything from "How to Make Ice Cream" to "How to Deal with Someone who has OCD." I've spent a few hours on the site over the past few days, and every article I've looked at strikes me as horribly wrong.
Just take a look at the vacuity and arguable incoherence of the entry on "How to be Good." Apparently being good is a matter of a mere 7 steps, each of which is nearly fully devoid of content: "Be Proactive"; "Be Balanced"; "Consider the Results"; "Consider the Greater Good"; "Give People the Benefit of the Doubt"; and "Be Good for its Own Sake"! Step 4 is particularly awe-inspiring: "Define what 'Good' Means to You."