Here's an annoying linguistic trend; people responding with "I know, right" or just "Right?!" This is even more annoying than the short-lived "Yeah, what's that about?!" When someone says "Right?!" after I've related something -- it sounds like they're saying, "Yeah, I thought of that too, only I didn't say it." Well, you didn't think of it, or you'd have said it. Saying "Right?!" means you're bereft of comment, opinion, and perhaps even thought.
"Cool" is another dunderhead response that says nothing and goes nowhere, and has moved from the highfalutin circles of skateboarders and 9-year-olds to the imbecilic confines of boardrooms and offices. It's an ideal conversation stopper, which again informs that the offerer has absolutely nothing to add, only to acknowledge that they're too unclever to proffer further analysis or even a "Right?!"
This really isn't new, I suppose, but still irksome, as these expressions join the horrible history of patois with "Groovy," "I can dig" and "solid."