Hypothetical Mash-up for Teaching

As part of the discussion during the seminar we are teaching with a wonderful group of post-docs from the FIRST program, a question was presented about an instructor's ability to annotate (comment and mark-up) student assignments on blogs. One possible solution is to use diigo to comment on the student's blogs and then to share them with each student and with the class. This mash-up might actually work. Now all I need is for this group of instructors to use this in their classes and report back on the success (or lack thereof) of these tools.