For teachers in schools that do not allow access to social bookmarking sites or for teachers of younger students, a Google Form can be a great way to introduce students to the idea of social bookmarking. Ask students to submit the URL and title of a page. You can have students select from an existing list of tags to begin (sample form where students have to select from an existing list of tags), then move toward students adding their own tags. Share with students the spreadsheet results and discuss why they chose particular tags.