When I first joined Twitter, IM was my favorite way to interact with the service. A long time ago, Twitter turned off the “track” feature. I was sad.
Now, with excla.im, I can get Twitter Search results as they happen via IM. This is an awesome way to track @ mentions. Bonus: if you set this up via Gchat, and you are not logged into chat, the notifications will fallback to email.
To setup, just add email@example.com to your Gchat buddy list, and send it an IM, “track searchterm” to get Twitter results for that term IM-ed to you.