I swore like a sailor when I was a sailor. I actually shocked a senior chief one time. (She was a reservist doing weekend training, but still — it takes a lot to shock a senior chief.) For the most part, swear words were little more than verbal ticks; the equivalent of "um" or "y'know," and with about the same emotional content.

When I became a civilian I needed to tone things down. Fortunately I had a reserve of Yiddish swear words, courtesy of my Jewish classmates in high school. UNfortunately (because the universe has a warped sense of humor) my first civilian boss was an Israeli. I let loose once on a piece of software that had made me VERY unhappy, then realized Giora was standing right next to me. He had a shocked expression. He finally ventured, "I really do not think that it was that bad..."

By the time I got to the company where I met Deb, I had switched to British curse words. Naturally, the president of the company was a Brit. (He ended up correcting my usage, occasionally.)

I now use "frak" a lot, from the Battlestar Galactica series. When I use anything stronger, Deb knows I'm either really upset, or my blood sugars are falling.