Group items tagged

A.nnotate.com lets you easily give, collect and store detailed notes on documents and web pages.

Free application that provides users the ability to document resources, bookmark sites, provide annotation, and has iOS app option too.  No Safari bar option available. 

1. Google Notebook is very much similar to Diigo Lists. In Diigo Lists, you can organize, share and display specific collections of bookmarks. Once you add bookmarks to your list, you can easily re-arrange the collections by drag-and-drop, and add "section". And you can publish a Diigo list as an HTML document. 2. In Diigo, an item in a list is also saved separately as a bookmark (which can be tagged). So in this sense, Diigo integrates both Google Notebook and Google Bookmark. 3. Diigo also has the important advantage that "clippings" are really "highlights" on the original web pages and will be shown as such when you re-visit the web pages, reminding you the exact context of the clippings. 4. Another unique Diigo list feature: once you create a list, click the " WebSlides" button, you can browse, play and annotate any list of URLs as a slide show! It's great for content browsing, sharing, and creating unique presentations based on web content.Here is an example of a Diigo List, consisting of recent reviews of Diigo, and watch the Diigo List / WebSlides in action! 5. Google Notebook is a bit more flexible in that an item does not have to be tied to a webpage. Diigo Lists will soon be upgraded to provide this flexibility and a lot more in the near future.

Upload and use documents or videos for online collaboration.

Not sure that this compares to Diigo's functionality except that you can upload docs