Crossing Your Arms Reduces Stress
Simply crossing your arms reduces the feeling of pain.
Since we generally use our right hand to touch things on the right side of our orientation, and our left hand to touch things on the left side, scientists believe that when you cross your arms the brain gets confused and doesn't process stimuli -- including pain -- as well.
Dr Giandomenico Iannetti of University College London tested this theory by using a laser to generate a prick of pure pain on the hands of volunteers, and measured both their neurological response to the pain (with a brain scan) and their perception of the pain. In both cases, the volunteers who were asked to cross their arms didn't process the pain as much.
While this form of pain relief sounds too good to be true, it's easy and it's free so you may as well give it a shot.