How do you set up javapns (push notifications for iOS)?

I have had a look at the documentation / wiki for javapns. http://code.google.com/p/javapns/

Unfortunately, what should be obvious is anything but obvious to me.

How do I set up a working push notification server? As in, there's a .jar file, but I would appreciate more info than that. Do I need to run this in Tomcat? Is there a working example?'

Thanks.