Many moons ago, I used CorkboardMe in class. It really grabbed their attention and we had fun with it. Unfortunately, one night, before we were finished with our group observations and the lesson, one of my super-sweet students deleted all of the notes. Purposefully. In fact, the culprit left one note--a letter of apology from another student. A nice touch.
Here's Wallwisher--a similar site. Here, though, you can post videos. I think this would be great for class and workshops or faculty meetings. I'm so tired of using markers on giant Post-It Notes. Also, it's useful for collaboration. In fact, I'm getting ready to create a wall, post a video, and e-mail it to my faculty--try to create some dialogue... They don't read my blog.
Write it on your communicator: Wallwisher.