We need to be clear about one thing; using a cell phone (talking or texting or ??) while driving endangers others, doing so while riding a bicycle or walking endangers only yourself. That's a huge distinction. I am strongly against any cell phone use while driving.

For bicycle riders and pedestrians I think we just need to apply some community peer pressure if they're cell phone is causing them not to pay proper attention. The vast majority of cell phone use while riding or walking has zero impact on anyone. A very minor amount becomes an annoyance. That's about it.