I've told this story on here before, but way back when I got a brand new super-expensive original iPhone when they first came out, hacked it over to T-Mobile and life was good. I had a case on it. One evening I was late for a plane and I was running across the granite floors at Denver airport with my coat slung over my shoulder and the iPhone was in the pocket. I turned a corner and started running really fast to make the plane, and I shifted my coat to my other shoulder by sort of flinging it across and the phone flew out of the pocket, and then - and I remember it in slow motion - it arc'd through the air and then landed flat-side down and slide across the marble a good 20-30 feet. Not a scratch on it - although again, I had a hard plastic case on it and the case was definitely scuffed up.
Another time I got out of my car at work, reached in and grabbed my iPhone 3GS off the dash and it slipped in my fingers, and went airborne, I grabbed it with my other hand and it bounced out of my hand, and then I intercepted it with my shoe and it bounced off my foot, and then it landed on the asphalt and there was no damage.
But while I've dropped my phones a few times - about once every six months - I haven't actually ever broken one. But I always have a case or at least a bumper on them.