Diigo is a powerful research tool and a knowledge sharing network

"It would be easy to dismiss Diigo as yet-another social bookmarking tool, but that would be a big mistake. Diigo's highlighting, bookmarking and site sharing tools are a subset of features in a rich collaborative application that puts information discovery and the writable Web at the center of discussions among colleagues, friends, and like-minded people. Diigo represents a move to maturity in the Web 2.0; it is a business tool, leveraging social models to deliver real value to its users." ~ Chris Shipley, executive producer of DEMO