I'm sure there are more examples of this, but play along if someone calls in for something that's not really a 911 call.
-A kid calls in about a math problem (Help them with the math)
-A guy calls in singing (You can choose to sing back)
-A guy calls in for advice picking up a girl in a bar (Memory foggy on this one, it was something about a girl though)
I got the achievement when the guy called in singing