Some days ago, I started to use twitter. I am not sure how it will works for me, but I will try to do some experiments with it.
What can I do with 140 characters? A web framework? Done in PHP?
Enter Twitto. Twitto is the first framework done in a tweet. That's right. Twitto fits in a tweet. Moreover, I have tried to use as much new PHP 5.3 features as possible.
Twitto even has its own website and documentation.
Of course, this is just a toy and you should not use it as a serious tool.