What is Twitter?
It reminded me of the time in my mis-spent youth when I got lost in IRC, spending evenings heckling the TV with my IRC friends. This is the geek equivalent of being stoner, by the way, with roughly the same effect on cognition . . . It's a very loosely-coupled conversation.
An interesting (but probably useless) hack would be to take an opensource IRC client and wrap it around Twitter's API.