Other
Delicious
This tool is an online bookmarking resource. It allows you to keep links to your favorite internet sites, access them from any computer on the web, and share favorites with friends, family, and colleagues.
Wikimedia
Wikipedia: Social Bookmarking
This article introduces the reader to the concept of social bookmarking which organizes sites generally by the use of tags. Social bookmarking sites are an increasingly popular way to locate, classify, rank, and share Internet resources...