I only found out about Twitter yesterday, but I’m already quite fond of it.
It’s basically a microblogging service that allows you to tell your friends what you’re doing or thinking.
What I like about it is that I can twitter not only from a browser, but also from my mobile phone, and from the command line using Net::Twitter in Perl. It’s also nice that I can display my most recent twitterings on my blog (see the top of the right-hand column).
Now I just need my friends to start to twitter, too.