This thread really took off. I have been using a tri-fold, front-right pocket, with keys. I have small keys. Good not great. I will consider bi-fold now.
How does anybody that's right-handed put their keys in their left pocket? Weird. Your right hand grabs the car remote, apartment door key, work door key, etc. Your left hand can open a text or check scorecenter or call the GF while your right hand does the other stuff.