Everyone knows Wikipedia by now (don't you? I mean my mom knows about Wikipedia by now) and it's popularity has spawned a Wikilution. Wiking for business is a new fad (move over business blogs!) and now there's the Million Dollar Wiki (doomed to failure as it's natural links could never overwhelm the spam links it will draw which will piss off Google no-end). But no Wikis seem to be able to live up to the standard set by Wikipedia.
But someone finally found a wiki niche that just makes sense. wikiHow is, in it's own words, "a collaborative writing project aiming to build the world's largest how-to manual." And, from what I see, it's a success. Keep getting an error 1418 on your iPod Classic? Well just put "error 1418 iPod" into wikiHow's search, and you get this. Too many martinis last night? Check out How to Get Rid of a Hangover. There are also plenty of articles that would fall under "advice" more than "how-to", such as "How to be Happy After a Divorce" or "How to Live Life to the Fullest"
And of course, being a wiki, you can add articles too. Know how to play the kazoo with your nose? Share with the class, dude! You can add your skills to the likes of "How to Get a Stubborn Horse to Jump", "How to Enjoy a Kung Fu Movie With a Friend Who Doesn't Enjoy Kung Fu", "How to Diagnose and Replace a Failed PC Power Supply", and "How to Copyright a Song."