This is something I've thought about last night and figured I'd explain my reasoning about this topic.
I am not claiming to have a completely clean mouth. I've worked in a heavy machinery shop for over a year and have been exposed to profanity quite a bit. I'm the first to admit that I too have a problem with profanity (mostly under my breath), but its something that I'm aware of, and try to work on. I also realize there are various levels of cussing. (GD word, F word, MF word, SH word, being among the worst) Lower levels of cussing don't offend me, but there are some who are much more sensitive then me.
When cussing is done in the workplace casually, it annoys me. First of all in the office we have a different standard than those who might work in construction, or where they have a more relaxed environment (dress, play loud heavy metal music, display topless posters, etc). I'm an adult and don't get upset when cussing is done in real anger or rage (I sometimes do that myself depending on the company present). But when those who cuss casually it annoys me and makes me wonder how intelligent they really are.
Those who do it should be more aware and considerate of those around them. It isn't professional and needs to stop. For more information on this topic and for helpful tips, visit http://www.cusscontrol.com/news.html
Although it may sound real stupid, using alternatives sure beats the real thing. Here is a song that plays on that idea which cracks me up. Done by one of my favorite bands - Evercleen.