I’ve written a custom notification plugin for TeamCity that will send build notifications via Growl or JGrowl.
You can get a copy here:
http://code.google.com/p/tcgrowl/
I’ve created a custom BuildListener for Ant that provides Growl notifications when your builds start/stop. It uses the JGrowl library to send messages. JGrowl also provides a Growl like notification system for any Java platform. I’ve also created an Ant task similar to <echo> that lets you send messages to Growl during your builds.
You can get it here: