Edmodo is an online microblogging system designed specifically for practitioners and learners.

• Using Edmodo practitioners can create a microblogging network for their classes.
• Edmodo allows practitioners to create a group specifically for their learners and exclude those not invited to the group.
• Edmodo provides practitioners with a place to...
  • post assignment reminders,
  • build an event calendar, and
  • post messages to the group.
• Users can share...
  • links,
  • videos, and
  • images.

Find out more for yourself at http://www.edmodo.com/ or watch a video at http://uk.youtube.com/watch?v=P39rn3Fp-_A.
or the embedded version below...