A couple of weeks ago. Locked my phone in my house along with my keys. I'm glad they're still around; when they're useful, they're very useful.
I doubt a payphone would be of any use to me without my mobile / laptop - the only number I remember is my mother's - just because she has it since the pre-contactlist times (I learned it because of dialing the digits often).
OTOH - I used a payphone 3 months ago (and before that... many years ago) in another country to avoid roaming charges.