Another idea for a patch

Hi KNB, I finally realized that the idea of writing a kernel patch to make brightness persistent across reboot was bad. I thought of another thing which could be done. In my laptop, there is a key called "Fn". Also, on some of the function keys, there are small symbols for a particular operation. Those keys coupled with the Fn key perform that particular operation. Now, Fn coupled with F6 key should disable the trackpad. But, it doesn't do so. It does disable trackpad in Windows though. Do you think this could be a suitable patch ? If yes, from where should I start ? On a separate note, I'm 1/3rd way across ldd3. Umair Delhi, India