I love my smart phone. I keep it in a ziploc bag in my jersey pocket when cycling. I keep a few bucks and an ID in the bag as well.

I use a cheap little cycling computer mounted on my bars so I can see my speed, progress, and the time. I also use a cycling app that tracks my travels, miles, etc. that runs quietly in the background in my pocket. I really like the cycling app.

I rarely get calls or texts while I am out cycling. But if I do.... I assume they are important and I stop. If I am expecting an important call.... I'll forward it to the smart phone.