Description: "Diigo is two services in one -- it is a research and collaborative research tool on the one hand, and a knowledge-sharing community and social content site on the other.... Diigo provides a browser add-on that can really improve your research productivity. As you read on the web, instead of just bookmarking, you can highlight portions of web pages that are of particular interest to you. You can also attach sticky notes to specific parts of web pages.... You can easily share your findings, complete with your highlights and sticky notes, with friends and colleagues."

Despite social bookmarking sites such as Delicious and Diigo, many of us still like to bookmark the old fashioned way - using our browser's menu bar. But, if we have to use multiple browsers and computers our bookmarks soon get scattered and unorganized. Bookmark synchronizers solve that problem by merging our bookmarks and storing them online for easy access. Below is a collection of all the bookmark synchronizing services we could find.