Thanks to some code from Brian Gottlieb, LEDBoard can also set your Yahoo! Messenger status.
To see this in action, check out the Arcade/PC Machine.
Since this program is mostly for my own use, it doesn't have configurable options for which serial port to use. If you're interested in having me add more features to LEDBoard, let me know. Otherwise, feel free to refer to the source code to see how to create a program that listens to the game names that MAME32 broadcasts.