You can change the code so that instead of printing a message, it performs some other action. You could for example have it control LED flashing, by combining the code and hardware from this tutorial with that of http://learn.adafruit.com/blinking-an-led-with-beaglebone-black

The same setup can be used for any size button and switch!

About the Author.
As well as contributing lots of tutorials about Raspberry Pi, Arduino and now BeagleBone Black, Simon Monk writes books about open source hardware. You will find his books for sale here at Adafruit.