This has been open in a browser tab for at least a week, but it's very cool... similar to using Ning to create your own social network, ShoutEm will let you create your own microblogging community. This is a bit like edmodo which was more focused on teachers and students, but I love the anonymous posting feature in ShoutEm. Steve Dembo has a good example here: http://teach42.shoutem.com/
Edmodo allows you to create a sort of closed social microblogging enviornment (like twitter) for students and teachers. However, for "real life" use, it's kinda lame. You have to know a person or group to publish anything. Also, for "safe" school use, it seems odd that as you type in a user name it autosuggests existing users.
Click in to find related links.