Opinions:
Diigo is an online-bookmarking-tool allowing you to highlight and comment on online text passages.
The internet is being used more and more frequently for research, exam preparations and so on. Writing your comments online like on printed texts was not possible for internet articles until recently. This is where Diigo can help. The tool allows to work on websites, just like highlighting passages in a newspaper article and writing notes on the page. With the Diigo Online-bookmarking tool, researchers, students and everyone else can do their online research work more efficiently and in an interactive manner.