1. Buy them a trip to Tahiti, a one way ticket of course. Sure this may be pricey, but so are the therapist and antidepressants you will need if you keep dealing with said annoyance. Also I truly believe in karma and treating your enemies with such kindness is a surefire way to have only good things come your way.
2. Pray for their families. If you only have to deal with the offender on a small scale, imagine the poor people who must live with that day in and day out. Bless their hearts, as my southern grandma used to say.