I'm a bit late to the game on this one, but McDonald's will give you a free 8 ounce Iced Mocha (or a 7 oz hot one, if you want) both this Monday and the next, from 7 am to 7 pm. The promo ends August 3rd.
I suppose this may apply only to participating restaurants, so check for the free promo posters at your local McD's, or look online at McDonald's McCafe site.
Have I tried 'em? Yep. Pretty darn tasty.