It's inbox backwards, a company started by a couple pals of mine from Y Combinator. Adam and Matt are turning this into quite a big deal. Bill Gates is no Steve Jobs when it comes to presentations, but having the word "xobni" come out of his mouth is definitely some kind of an accomplishment. (See, even Bill pronounces it Zahb-nee, not Zohb-nee).
I've proudly had my Zahb-nee button (over on the right) ever since they rolled it out, which I'm certain has been crucial for all of their success. That's a nice "unique display area" you've built, pity I still use Gmail, but I know there's no shortage of Outlook users who'd love to make their email habits significantly less painful. Congrats, guys.