I have been hearing more and more about Edmodo. It came up at NCTIES last month. I signed myself up for Edmodo, but I haven't started using it yet. (My group code is 39z8jh.) It looks a lot like Facebook and I am sure that my students would LOVE it. You can send messages, but students can't send them directly to each other. They can only send them to the teacher or the whole class. You can give assignments on Edmodo and track grades. You can even give the parents a code and let parents track their student's activities on Edmodo.
A colleague mentioned at bus duty this afternoon that her first grade classroom may go paperless next year. She asked me about keeping a Web site to post homework information and other updates for parents in place of paper. I almost did a cartwheel on the sidewalk!! I told her that we have many free tools for creating quick Web sites Pbwiki, Weebly, and Blogger. However, I suggested that she consider Edmodo. And she had heard of it too! So I think we will be going on an Edmodo adventure together.
One of the advantages I see for Edmodo is providing a safe social networking platform for teachers to interact with their students. I can imagine using it as an opportunity to discuss social networking outside the classroom with my students. It is definitely a great 21st century tool!
I am going to be looking for feedback from other teachers (especially K-5) who have used it. Here's the first one I found, http://blog.web20classroom.org/2012/03/why-you-should-give-edmodo-try.html.