Since then, I've done some studying on the subject and while I recognize it's not the ideal way to reference God, I've also come to the conclusion that it might not be the worst sin** in the world, either.  What's ironic is that oftentimes these phrases are used in a moment of heated aggravation and they may the closest thing to a prayer many unbelievers will ever say.  What's more, when people use these phrases, they support the exclusive authority of God (you don't hear people throw Buddha's or Mohammed's names around so commonly).

Regardless, taking the Lord's name in vain is a sin:

It ticks God off, that much seems pretty straightforward.  The reason it's such a problem is that when we use His name out of context, we misrepresent Him.  His name is not intended to be used in a fit of angry condemnation and it's not intended to be an absentminded response to bad news - it's not a swear word.

However, I think the real problem comes when Christians become so consumed with using God's name correctly that they miss the spirit of the command - we're not to misrepresent God.

But we do it all the time.

Every time we cut someone off on the highway with a fish bumper sticker on the back of our car... every time we ignore the cashier who's serving us as we spend our time chatting on the phone while wearing our cross necklace...   every time we avoid eye contact with the homeless person because we don't want to be late for church... in all of these instances we misrepresent God.  

And as believers our violation is worse... we know better!