This little tidbit spotted at the Huffington Post.

So here’s the deal. When you want to announce or proclaim something, you might annunciate it. (I didn’t think this was an actual word but apparently it is. Like I say, you can teach an old MRP new tricks, although this word doesn’t appear to be in regular usage.) When you want to carefully pronounce a word so that you are understood, which is apparently important to Perez Hilton, you enunciate it.