No, they ain't funny, a good part of the time. It's probably not a good idea to give a facetious answer to a serious question when (1) the person you're answering is a stranger, not a friend; and (2) it's your job to give customer service.

Now, having said that, I'll give you a couple of examples of quick-witted replies I have witnessed.

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Bob and Vern were two of my coworkers who liked to tease each other about getting old.

One day Vern was walking around the office with his fly accidentally open, until Bob pointed it out to him. Then Vern said, while he zipped up: "Well, you know what they say; it pays to advertise."

Bob replied, "Advertise? What have you got to advertise? Are you having a going-out-of-business sale?"

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This exchange was between two physics students. I'll call them Al and Sammy.

Frank was moaning about an experiment that had gone wrong: "Why does this always happen to me?"

Sammy said, "Maybe you're stupid."

Frank was used to this kind of abuse from Sammy, so he didn't get mad. He only complained: "Sammy, that was a rhetorical question. It doesn't require an answer."

Sammy replied, "Well, that was a rhetorical answer. It doesn't require a question."