I think the pushup is one of the better exercises available for building strength not only in the chest, shoulder and triceps but in the stabilizing muscles such as the upper back, mid section (both abdominal and lower back) and the hip/leg area. For some odd reason, it is often overlooked. Maybe because it isn't high tech or complex enough or maybe it's under valued because a lot of people don't truly understand its worth.
It takes more than just upper body strength to perform a pushup and it can be quite challenging -especially at the end of a workout when the body is tired. A properly performed pushup involves the entire musculature and when incorporated in a strength - body building program it can provide tremendous results. I mean, c'mon, how hard is it to pop of some pushups a couple of days a week, right? – Fred Fornicola