By Derek Bruff in The Chronicle of Higher Education, November 6, 2011. The author discusses multiple methods of sharing academic information: social bookmarking, back channels and collaborative documents.
Produced by commoncraft, Aug 6 2007. This video describes social bookmarking in a fun and decidedly low-tech fashion. Runtime is just over 3 minutes. Please note that this video is for sale, though it is possible to watch an evaluation copy, for free, from this URL.
By Laura Spencer, published in Freelance Folder, Jan 10, 2010. While targeted to freelancers, this article provides an excellent overview to Diigo features, and clear instructions for how to get started. It is current and all examples are for the current version of Diigo.
By David Pierce, published on Makeuseof.com, November 8, 2008. This post outlines the advantages of Diigo over Delicious (both social bookmarking tools).
By David Hayward and originally published in April 2009 Integrating Technology column of Beyond Penguins and Polar Bears; here it is part of the blog Expert Voices published by the National Sciences Digital Library. The post provides a great overview of Diigo, with advice on how middle school teachers can use it.