The Bod Pod is the latest technology in body composition testing.  It uses air displacement to measure body volume and then predict percentage of body fat.  It requires you sit calmly in the Bod Pod for <1 minute wearing a swimwear or spandex clothing and a cap.  It is highly accurate, very easy and provides instant results.

The skinfold method uses a caliper to pinch three sites: leg, torso, and upper body.  The sum of skinfolds is used to predict overall body fat.  This method is very fast, but less accurate than the Bod Pod.