I remember seeing the same joke (more or less) in King of Queens. Arthur is reading a phone number aloud one digit at a time, and Doug is dialing it.

A: Two,
D: (dials)
A: three,
D: (dials)
A: nine,
D: (dials)
A: six,
D: (dials)
A: -teen...

I should have known it had a long history.

Re: Perl's "unless", I use it very rarely, and only in the postfix form.