Rule #3: Please, no cell phones here.{relatedarticles}
Most gyms have banned the use of cell phones in the workout area. Even if it is allowed at your gym, it is really looked down upon. Sitting at a machine on a phone does not look like resting -- it looks rude. The gym is a place to put life on hold for a bit, so unless it is an emergency, keep it in the locker room or car. If it is an emergency, use it away from the equipment. It wasn't long ago that cell phones didn't even exist, and we managed just fine without them. One hour in storage won't kill you.
Rule #4 Rack those weights when you are done.