What are some things I can do to occupy myself while maintaining post at a desk without responsibility?

I have a part time job at a fitness center and my only responsibility is to wipe off machines once every hour, and pretty much just be available incase someone needs help or there is an emergency. Besides those menial tasks, I have to sit at this desk for nine hours today and I'm going to go insane! I have a short attention span to start with...what can I do to help make the time p?