Solution
AddThis
AddThis is a popular bookmarking button aggregator that provides supporting analytical tools.
Del.icio.us
Del.icio.us is one of the early pioneers of social bookmarking now owned by Yahoo! Content is filtered by general popularity.
Furl
Furl is one of the early developers of social bookmarking, now owned by LookSmart. Content is filtered by general popularity.
Digg
Digg is the largest social bookmarking network which initially focused on the technology community and has expanded into other categories. Content is filtered by "diggs."
Sphere
Sphere is a social bookmarking service owned by AOL. Sphere connects your current articles to contextually relevant content from your archives as well as from Blog Posts, Media Articles, Video, Photos, and Ads from across the Web.
StumbleUpon
StumbleUpon is a social bookmarking and content discovery service owned by eBay. Clicking the Stumble! button will help match content recommendations to your personal preferences.
Mixx
Mixx is a social bookmarking service that helps you discover relevant content based on individual preferences.
Yahoo! Buzz
Yahoo!'s social bookmarking service that incorporates user activity on Yahoo! mail, search, and other areas across Yahoo!
