Diigo 3.85 (A/A-)Diigo is by far the most fully featured social bookmarking site in this list, and offers several unique capabilities. The most notable feature is that users can highlight text right on the page, as well as make annotations via a “sticky note” for later viewing.There are also other very useful features. I particularly liked the sophisticated and advanced search option for doing a keyword search of one’s own or public bookmarks. On that page you can limit a search by a phrase, and restrict a search to a URL, title, comments or highlights. You can even search “on” specific users as wellNote that when you place a “sticky note” to comment on a page for your later viewing, that note is viewable by anyone else in the Diigo community that views that page too! .There are some other interesting and unique features on Diigo. For instance, when highlighting a word on any page with Diigo’s bookmarking tool, a drop down menu automatically appears that allows users to search for that highlighted word on various search engines, social bookmarking sites; blogs, on the active site and more. I also had much more control in formatting when saving a page; and had an option to forward the page to another person as well.What about the all important group feature? Well, Diigo rounds out its offerings very nicely by just this month launching its “Groups” function. That feature looks to be a clear and elegant way to allow anyone to set up a private environment for sharing your bookmarks. Ultimately, if you combine the Web annotation capabilities with the ability to share in groups, Diigo has created a very enterprise friendly social bookmarking service. And, according to a spokesperson at the firm, this Groups function is “just the first of many more advanced group collaboration functions that we will be introducing in several phases” So we look forward to staying tuned!My Grades:Group Function Capability: AResearch Value: A-Design/Interface/Ease of Use: A-Fully Featured: A-(only missing “related users” and “larger topics”)