I still pay my rent every month per check, and only per check (the landlord insists, I don't mind). I also do occasionally receive checks for very insignificant amounts of money in the mail, e.g. few cents back from insurance or stuff like that. That's always a bit funny.
Someone living in San Francisco excitedly! told me just 1-3 years ago that they could now use some 'photograph your check' feature on their mobile - not 100% sure where the checks were used, but said person was not used to using checks where they came from.. sounds kinda widespread.