Folksonomies

I don't use that many sites based on folksonomies, except Wikipedia (using folksonomies?!). The idea of letting people input
and create content is a direct democratic implementation of technologies, but this is, just like democracy, prone to be backstabbed by its own good sides; the ease of modification, and the risk of giving equal rights to people misusing them could in a worst-case scenario become its own fall. Evil clairvoyance set aside, letting users form paths and content based on patterns less linear than the traditional "easy-to-follow" guide lines has proven to work as a more flexible, living way to "bump into" information, instead of merely tracking it down (this is more in regards of sites like Youtube and Flickr).

As my own example of a page I use, I (unsurprisingly) wish to choose Wikipedia. Wikipedias core is its decentralized structure, based upon direct user contribution. It has managed to thrive due to the fact that people have taken seriously on their commitment to the information provided on the site.