Those that cannot handle unimaginative crude language should just not read this post.
TORONTO, ONTARIO - A German colleague once told me, "The English language has this wonderful word, 'shitty.' You can use it in so many ways and convey implied meaning. The German language has nothing like 'shitty.'" Perhaps obviously, he was being ironic, trying to insult English speakers for being lazy with imprecise language and pointing out that his native German had more precise demeaning adjectives for different situations.
However, by using the word in a joke, he was demonstrating perhaps the most noble use of that word and the four-letter noun from which it derives--in humor. Take this piece from the Onion News Network. Would it be nearly as funny if they had used, say, the word "stuff" instead of the bovine version of the four-letter word? I think not.
My all-time favorite use of the four-letter word was on a summary of comparative religions. The GNU humor archive has an on-line version of the piece. Would it really be as funny if it listed Confucianism as "Confucius say 'Garbage happens'" or Catholicism as "If garbage happens, it is your fault"? No way.
As a clearly colloquial word, the four-letter s-word conveys a casual, less than profound mood. The very vagueness of the word gives it a joint flexibility and universal inappropriateness, above and beyond its appearance on the list of seven dirty words.
Other "swear" words have little more than shock value (and less of that every year). For all the supposed part-of-speech flexibility of the "f-word," it isn't very funny. Richard Pryor, amongst others, made a career of using a variety of foul words, and for the most part, wasn't actually that funny.
It takes skill to use a swear word in a truly humorous fashion where it actually adds to the humor. The "s-word" seems to be the most useful in that regard, and my German friend and the Onion understood how to use it properly. Why haven't I used it, except in a quote? I know this piece isn't funny, and using it wouldn't help. If laughter is needed, go back and view the links again.