Ellyssa Kroski has written one of the best articles I have read regarding Folksonomies and User-Based Tagging. This complete look at the topic is an excellent read if you are interested in folksonomies or are integrating tags into your next web application.

Wink is a new breed of search engine and public bookmarking site that gives you the most relevant and interesting results as found by people! Wink uses Google powered search and applies Wink’s PeopleRank technology to deliver sites that people think are the best for your search. PeopleRank is a feature similar to Digg, where users of Wink can give each link a “Wink” to indicate that the site is good. Wink also makes extensive use of tagging to help find related links.

Information architect Thomas Vander Wal, has a good article titled Tagging for Fun and Finding that discusses the great benefits from tagging if it is done well.

I often have a difficult time explaining exactly what content tagging is, and even when I do explain it really well, most people have a hard time understanding what it’s inherant benefis are. Linda Zimmer has come to the rescue with a nice article titled - Tagging: What is it Good For?