As reported by WriteGrrrl by way of the dubious compiler of information (or is that the compiler of dubious information?) Wikipedia, there has, for some time, been a such thing as... an irony mark.
Now, we know the evils of ALL CAPS and exclamation point abuse (many ranting web posts later), but we have to definitely leave it to the French to come up with a fabulous system of cues to make sure that everyone gets the wryly wrinkled brow, the ever-so-slightly sneering lips, the deadpanned expression, or the rolling eyes that make up our friend irony both here and abroad. Oh, why don't they teach this stuff in school?! Why isn't an irony symbol on everyone's keyboard?
Apparently, French novelist Hervé Bazin came up with quite a few more symbols, including one for certainty, one for authority, and one that looks remarkably Spanish in origin for indignation. Now if only we can figure out how to make irony easier to explain...