After nearly dropping my phone too many times while riding I decided to make a handlebar mount for it. If I want to hit the "ignore" button it makes the phone easy to reach rather than trying to fish it out of my pocket.
Whenever I find scrapped bikes at the local transfer station, i.e. dump, I pull the plastic reflector, pedometer, or light loop brackets that almost always remain. These parts are handy for many projects, not just bike related ones. The el-cheapo phone holder came from Target but similar ones are found at Pep Boys, Wal-Mart, or discount stores for a few dollars. A rubber band is used to get the phone snug when bumps are hit.
The only tool needed was a Phillips screwdriver. I was lucky in that the phone holder had a slot along the back to drive the reflector screws into. The reflector L-angle was aligned over the slot. I played mix & match with the various loop bracket machine screws on hand until I found one long enough to clamp loop to the handlebars and accept the reflector L-angle bracket. All in this mini instructable to longer to compose & publish than to execute.