I rarely use my phone hands free for more than a few minutes and don't like the bluetooth hassles. I keep one of these in all my jacket pockets, hang one from the rear view mirror on the car and one or two around the house.  They last forever and no one ever complains that they can't hear what im saying.  On the odd time I use my motorcycle, it also fits easily under the helmet and if its a longer trip, i just take a small (easy to remove!) band aid and tape the mike to my cheek.