Social Bookmarking Showdown
Wired has a nice piece this morning listing some of the best and most popular social bookmarking sites available out there. The article gives a quick overview of each service and lists most of their pros and cons. A worthy read for the social bookmarkers among you.
There's a score of services out there, and no single service has it all. Some social bookmarking sites focus more closely on sharing and discovery, while others offer more options for sorting and organizing.