Folksonomy
Mathes, Adam Folksonomies - Cooperative Classification and Communication Through Shared Metadata
Hicks, Tags Turning Web Chaos into Categories
Porter, A User-Driven Approach to Organizing Content
Levy, Steven, In the New Game of Tag, All of us are it.
ScreenCasts
Udell, Jon, Screencast on Delicious , Screencast on combining blogs/delicious: on demand blogosphere
Tools
Tags at Technorati
Notes from an Information Architecture Summit Workshop on Folksonomy