This is a great reference - the Bloom'g Digital Taxonomy Summary Map - of taking the social media one step further to harness it's power! Scroll down on this website to the graphic organizer which shows you where these web2.0 tools fall on Bloom's Taxonomy!
This wiki has rubrics for assessing students at various points in Blooms Digital Taxonomy. Great tools are available. Wiki was awarded 'Best Educational Wiki 2012' by the Edublog awards.