I know I haven't posted in a while, but I saw a post on Samurai Knitter's blog today that got me thnking, and I wanted to comment. But my comments kept growing and I decided (like at least one other reader there) to just give it a whole post of it's own.
Like Alwen, I kind of subscribe to the theory that words have power, and the more seldom you use certain words, the more impact they will have when you do use them. I rarely swear, so when I do, it means something. I am either making a point, and people are shocked enough by it to pay attention, or I am extremely frustrated and it is really cathartic. (I also have a very even temper as a general rule, and a really long fuse, but when I reach the end of that fuse, the resulting explosion can be heard two counties away, and my husband cowers in fear.)
I find that I tend to have a low opinion of people who curse with every other word out of their mouths - whether for right or wrong, I tend to think that they aren't intelligent enough to express themselves without resorting to the lowest common denominator. Just my own personal bias. I don't find "comedians" who swear constantly funny either.
My son knows most of the common swear words, but we've always told him that part of being mature enough to know them is knowing when it's appropriate to use them (and it's almost never appropriate for a 10-year-old to use them!), so he doesn't use them gratuitously either. He hears us finding creative and eloquent ways to express frustration and anger, and my hope is that he will do the same.
That being said, in the right context, swearing can be hysterically funny - one of my favorite scenes from the movie "Four Weddings and a Funeral" is the opening sequence, where Hugh Grant is rushing around, running late, and muttering to himself "Fuck, fuck, fuckity-fuck-fuck-fuck!" Makes me laugh every time!