One of the paradigm-setting open-tagging systems that allows users to share links to “favorite” online resources and annotate them as belonging to particular categories of interest:

“del.icio.us is a collection of favorites – yours and everyone else’s. Use del.icio.us to:

• Keep links to your favorite articles, blogs, music, restaurant reviews, and more on del.icio.us and access them from any computer on the web.
• Share favorites with friends, family, and colleagues.

• Discover new things. Everything on del.icio.us is someone’s favorite – they’ve already done the work of finding it. Explore and enjoy.” (from About on del.icio.us site)

  Starter Links: del.icio.us home page