StumbleUpon

Recently i came across an excellent firefox add-on : StumbleUpon !! StumbeUpon installs a toolbar in your browser and lets you collaborative rate content. This improves the recommendations for other users and behavior matching is used to find users like you and pages that you haven't seen before, on-demand. One indicator I use for the popularity of a social bookmarking site is how much inbound traffic I get from it, and I've seen a clear switch during the year from del.icio.us bookmarks to StumbleUpon referrers. StumbleUpon reports that it has over 1.7 million registered users and growing. Bottom Line: Del.icio.us is still my favorite bookmarking service, but for true content discovery, StumbleUpon now makes it much easier to find new content than del.icio.us does. StumbleUpon is a winner by a nose for taking content discovery to the next step.