If you’re not sure what social bookmarking is, make sure to check out this video, from the Common Craft people.

There are many social bookmarking services out there, but the one I’ve grown to depend on is Diigo.  Diigo has a few features that I believe set it far above other social bookmarking services.  This is mainly because of the annotation features it has.  You can annotate saved web pages through both the addition of comments and highlights on the page.  These annotations can be private, so only you see them, but you also have the choice to make them public, and through this, start a conversation on any webpage on the internet!