If you're not familiar with Edmodo, it describes itself as being "a secure social learning network for teachers and students" — a sort of private Facebook, if you like, which it certainly resembles in appearance and functionality. The video here comes from their "About" page.
In the video, Edmodo co-founder Nic Borg says "Everyone is connected everywhere they go now except for within the classroom. They enter this void where the tools that connect them to one another don't exist any more". It may not (yet) be true that everyone is connected everywhere, but it's certainly crazy for the "technology" used in language teaching still to be limited to the printer and the photocopier.
Since first starting to use it on our Cert ICT course last year, Edmodo has become my favourite Web 2.0 tool. Again in the video, Jeff O'Hara says that for teachers "Edmodo is transforming the way they teach".
One change using Edmodo has meant for me is that, since I set up my first group I've never made another photocopy. I'm old enough to remember the pre-photocopier days when we cranked out copies on a mimeograph and I later spent years swamping my learners with bits of rainforest pulped into photocopied A4 sheets, which were handed out, used, but never seen or used again.
No one ever "replied" to a photocopy. Edmodo changed that.