Locating similar websites can be a challenge--here's a quick way to seek alternative websites. Looks interesting! Good to share with kids too. I think it could be described as a targeted search engine.
Blog about tools for drawing diagrams--free ones as well as paid ones. I particularly like (Inspiration--$ because you can hyperlink and save as a Word document with hyperlinks too--as well as bubbl.us--free.
mp3 collection of 'free' stories and poems; can search by author, title, reading level, content. All have PDF of passage so can be read as listened to.
Upload photos, record voice and share...free. Again, I see potential for publishing--could have book reviews, commentary and more on classroom webpage.
Spaaze is free (at this point)--cork board that can be used as a display board--video, mp3, digial images and more. Might work well for a project summary (group or individual).