I think swearing has its time and place. I try my hardest not to swear at work (at least, loud enough to be heard *whistles innocently* and never at customers!), or among children, but on MSN, talking with friends, in a relaxed atmosphere with older people, I feel it's fine. Also, it's best to to swear to insult someone, or to intentionally hurt them. That's just not cool.
That said, I swear a lot at home that sometimes it's embarrassing. 8) At work I keep it to a minimum, so much so that when I do swear loud enough to be heard, everyone gets all shocked about it. My co-workers think it's funny. I'm still left going "bwuh?" because like I said, I swear a lot at home...