Mike, your definition of irony in the first post in this thread was not quite right. If someone has a near accident, involving someone else, but manages to avoid the actual event by sheer luck or the intervention of some deity, and looks scared or sheepish afterwards, and you yell "Nice driving!", that's irony. If the driver nearly causes an accident and then acts as if nothing happened and you yell "Nice driving!", it could be irony or sarcasm, depending upon the tone of voice you say it in.

- Pfranz