I don't think cell phones cause lung cancer or emphysema. The better comparison is to caffeine. Yeah, it's pretty addictive. But it doesn't kill you. That's about where the cell phone is for some people. (And hey, the blue light even screws up your sleep cycle supposedly. As a long-time drinker of caffeine, I don't even HAVE a sleep cycle! Take that, cell phones.)
Also, I am guessing that most doctors would not recommend smoking a pipe a couple times a week. I doubt it's harmless.
Pipes are basically nothing in comparison with cigarettes, though.
My dad's doctor didn't quite recommend he start smoking his pipe again, but he didn't really try to dissuade him, either. It enhances his experience and he's old enough that any remaining cares about cancer are moot.
Also, I am guessing that most doctors would not recommend smoking a pipe a couple times a week. I doubt it's harmless.