Del.icio.us

del.icio.us is a social bookmarking site. The user bookmarks a webpage, entering it's description, title and they tag it. Bookmarks can either be public or private. Public ones are shared with other users, and are also available through an RSS feed.

[http://www.searchenginejournal.com/index.php?p=2642 Yahoo! bought it in December, 2005]. Yahoo! also own Flickr.