TwitterSpy is a supplemental XMPP bot for twitter that does the stuff the
twitter one used to do, and a few things it didn't.
The first thing you need to do is add im@twitterspy.org to your roster:

In order to post, follow, leave, etc… you must first login. You do this by IMming the following message:
twlogin yourusername yourpassword
After a successful login, you can post using the post command as follows:
post Hey look, I'm posting from twitterspy.
twitterspy will tell you when you have successfully posted a message.
As a shortcut, if your message begins with @, it’s always assumed to be a post:
@dlsspy Look at me responding to a post.
Though it’s not recommended, you can post without having to start every post with the post by enabling autopost using autopost on.
Any text you enter that cannot be recognized as a command will be blasted to twitter. Some people really like this. Personally, I find it dangerous.