I think Wallwisher.com is great. I created a board for compliments and sent it out to other teachers in the school. Our class is really focusing on behavior, so I think this will be a great way to encourage them! Here is my wall:
I also like blogger.com. I am going to start my blog with a discussion about our read aloud. Students, either on the netbooks or in lab, can comment and or question the story. I think this will be a great way for everyone to be heard.