Scrawlar lets teachers create virtual classrooms, lets students write and use a “whiteboard,” doesn’t require student email registration (just a classroom password and a student-created sign-in code, and is free. It’s also usable on laptops, desktops, tablets and phones.

It doesn’t get much better than that!

For now, I’m adding it to The Best Sites That Students Can Use Independently And Let Teachers Check On Progress, but I assume I’ll be adding it to other “Best” lists, too.