How can I be productive while doing almost nothing?

I just got a new job as a valet and it has been incredibly slow. In the past three hours I've parked one car. Being at a mall working alone for now I have nobody to talk to in all this down time. I try not to go on my phone so it looks like I'm at least attentive, so just being on Reddit all day isn't really an option. Oh well. Any ideas as to how to pass the time, maybe from anybody that has had similar standing around jobs? I just hate this feeling of a day going down the drain while making minimum.