Great bookmark tool - Diigo

I am using Diigo more frequently now to save my bookmarks. The more I use it the better it feels. Most liked features

1. The ability to tag bookmarks
2. The ability to form groups
3. To share bookmarks at individual, group and public levels
4. To find community bookmarks by tag, category, etc.
5. To annotate a particular bookmarked page and share it as well.
6. The integration with Facebook and Twitter
7. The toolbar greatly enhances the experience
   

This can be a great tool for a quick internet research based collaboration project