I like to use Diigo Toolbar Rated 5 out of 5 stars

Diigo toolbar is really great for daily internet users. Bookmarking, sharing, group and sidebar are best options in Diigo. I was using Delicious to get it done but Diigo is providing such a unique facility to save daily web surfing data with unique method and technology. Thanks to Diigo team!

This review is for a previous version of the add-on (5.1.0.29).