Meh.. I think people who are offended by “blasphemy” are being too sensitive, personally. When you exclaim “Christ!” when you stub your toe or something, all you’re really doing is demonstrating that you don’t cherish some of the same things they do. But really- isn’t that pretty much part of life? Different people, with different backgrounds, are going to respect & cherish different things, almost by definition; get over it.
Of course, it’s to be expected that such a demonstration will increase the social distance between you and people who don’t share your outlook – simple because you don’t share the same outlook. But being offended by your worldview (i.e. being offended that you don’t share their worldview, while not caring about what your own worldview might be) is a little silly, verging on hypocritical. IMHO.
On the other hand, if you’re going out of your way to offend people with profanity, then they’re right to be offended, since your whole purpose then is to disrespect them – in that case, you’re being a jerk on purpose, which is somewhat offensive. But it doesn’t sound like that’s what you were doing here.
Not to offend any of the Christians who have also answered this question; some of you gave very cogent and kindly-worded answers. :) I just happen to disagree with you.
Side question to those who are offended by blasphemy: why do you give others the power to bother you that way?