The linguistics of swearwords are interesting I think. They need to be taboo or they don't work. A certain amount of offensiveness is needed for their function.

I think swearwords are very useful. Both when used of emphasis, comedy or (their original use) venting frustation or pain.

And they have secondary uses as well. When someone swears a lot in inappropriate situations you can tell they are generally inconsiderate persons. And when somebody gets very upset by swearwords you know they are probably overly religious. For both things it's nice the be forewarned ;-P