Side-by-side comparison of Diigo, Del.icio.us, and Zotero from someone who was using all of them but decided to switch to just Diigo. While admitting that this is the right personal choice, he's not convinced about whether it's the right choice for schools to introduce social bookmarking.
Diigo User Communities ~ Stephen's Web ~ by Stephen Downes
Stephen Downes linked to me twice in one post. W00t! This is a nice overview of the flurry of activity around Diigo over the weekend, with links to a number of posts from educators exploring the new version.
Diigo sandbox in elluminate in 1 1/2 hour... | Diigo Message System
Message conversation on Diigo including suggestions from Maggie Tsai on a step-by-step path to introduce/explore Diigo. This starts with the basics and gradually adds features.