Cloud, mobile, social (i.e. sharing) - three 'buzz words' that are constantly being heard in regard to technology. Many of these web-based tools are very useful to enhance teaching and learning in the classroom as well as online. All of them are lifelong tools that can enhance personal and professional interactions, collaborations, and communication.
Diigo is described as a "research and knowledge sharing community". I create course groups for my students and build a professional development library with relevant content that students can continue to use after the course is completed and they leave the institution. This can easily become an annotated bibliography that provides students with resources on an ongoing basis. Diigo is a lifelong technology that is mobile, i.e. accessible anytime, anyplace, on smartphones, tablets, or ultrabooks.
In her blog post "Diigo for Professional Development", Dianne Krause provides additional thoughts and perspective for your consideration. Diigo is an excellent technology for both students and faculty as they collaborate, communicate, connect, and co-create knowledge.