If you want more of a "walled garden" approach, consider using Edmodo (http://www.edmodo.com). It's like twitter, but specifically designed for teacher-student communication. You control who is permitted to access your group, so…
Hi Gerald. I was wondering if you have students or educator contacts who would be interested in participating in a nationwide SAT Vocab Video Contest @ MIT university. You can view contest details at BrainyFlix.com Please let me know. Thanks!