KeyTouch is an application designed to allow you to make full use of all the special function keys on your keyboard, whether the hardware supports Linux or not. It's a great idea, especially with all the multimedia applications that come standard with today's PCs. But as is often the case, the devil is in the implementation details.
Marvin Raaijmakers wrote the first version of KeyTouch in 2004, after finding he could not configure the extra function keys on a new keyboard he had just bought. Today, KeyTouch is included in most modern distributions (Mandriva, openSUSE, Fedora, and Ubuntu, to name a few) and the project is actively seeking packagers for other distributions. If you want to download and compile the application yourself, you'll need to have the development versions of libxtst and libgnome-menu installed.