2005
del.icio.us
by ygirod & 144 othersdel.icio.us is a social bookmarks manager. It allows you to easily add sites you like to your personal collection of links, to categorize those sites with keywords, and to share your collection not only between your own browsers and machines, but also with others.
1970
Social Bookmark Tour - sbttt
by onechainmanCan you make the whole trip? Leave a comment or two along the way.
diigo - Social Annotation: Seamless Integration of Social Bookmarking, Web Highlighter, Sticky-Note & Clipping
by coxtree & 45 othersSeveral powerful features are seamlessly integrated to make Diigo a real "power extension" and must-have for anyone who browses a lot of stuff online.