I’ve written previously about some possible practical uses for Twitter (here and here), but if you you need some basics on the idea behind Twitter, there’s no one better than Lee LeFever to put it in plain English:
[youtube=http://www.youtube.com/watch?v=ddO9idmax0o]
Update: Check out Twitter 140 for a helpful further explanation.
Homework Assignments:
This is just the 101 class, so the homework is limited: