http://www.faviki.com
Faviki is a social bookmarking tool which allows people to tag webpages they want to remember with Wikipedia terms.
Unlike classic tags, which are just words, "Wikipedia tags" represent references to unique concepts that have their own URL. So, instead of having different tags for the same concept, which is the case with classic tags (cocacola, coca-cola, coca+cola, CocaCola) there are just the one unique “Coca-Cola” tag everybody uses.
You can register or just sign in as demo/demo and try it with bookmarklet.
The webapp is still in beta, but I just wanted valuable feedback from the YC community to help in next iterations. Thanks!
Definitely a good job overall!