SemanticScuttle

SemanticScuttle (based on the previous incarnation Scuttle) is a bookmarking tool that can take the ‘social’ part away. That is, you can install SemanticScuttle on your school server if you are concerned about any of the ‘social’ (or lack of privacy for students) aspects of other social bookmarking sites.

There is more information about SemanticScuttle on their wiki.

SemanticScuttle wiki

SemanticScuttle wiki

For schools that are concerned about cybersafety, SemanticScuttle could be a good introduction to the skills of using social bookmarking tools without any of the stress that comes with connectivity to the outside world.