Is the iPhone's technological prowess enough to compensate for the social disaster it has enabled? Has it made us happier, more productive, and more creative, like Steve Jobs seemed to promise back in 2007? If Leonardo da Vinci had had an iPhone, would his biggest accomplishment have been unlocking all six Temple Run characters?"Put it down, go outside, and take a damn walk." But not if you're reading this blog on an iPhone. In that case, keep it on.