Edmodo is a project that a friend of mine, Jeff O'Hara, has been working on for a while. He just recently released a teaser screenshot of the UI and it looks like it's coming along really nicely. I know Jeff's been working for some time to simplify education-related communication, a field that could certainly use some fresh ideas. It looks like they're getting close to an alpha release, so it should be fun to keep an eye on.