Here's my Rollyo. It could be used as a lesson in Information Literacy on how to evaluate websites for high school or college students. I had a crazy time with the Rollyo site and probably won't use it again. I would actually prefer Diigo or Delicious sites for this purpose as I like both interfaces better. I know it is not exactly the same concept but would certainly serve the same purpose...grouping webpages together under one tag so you can share them with a class.
I will certainly add more later, but I think a need a "technovacation" right about now. ; ) ~Steph