American Association of School Libraries Top 25
While doing research for a library school paper, I stumbled upon the American Association of School Libraries (AASL)'s Top 25 Websites for Teaching and Learning.
Included in their list is the EdLab's very own Vialouges!
I've been playing around with some of the other sites, especially Stixy.com - a note-taking website that organizing your notes like a bulletin board. You can see one of my Stixy boards here
(where I've organized the research for the original paper).