Diigo is a social bookmarking tool allowing bookmarking and sharing of websites, web annotation, collaborative research. Diigo V5.0 has added additional data types (screenshots, pictures, notes, etc) and platform support, such as Chrome, Android, iPad, iPhone, etc. Diigo offers cloud-based personal information management (PIM) service that enables users to collect, highlight, access and share a variety of information, on a variety of devices. It has a Diigolet bookmarking tool which can be added to your browser toolbar to enable you to harvest web page details. You can also create and share resource lists.