Very smart (smart = book).
Super clever (clever = witty).
Love (love = adore) it/him.
I came across his stand-up act on Comedy Central...and a couple of weeks later, noticed that Kristin had become a fan of Important Things with Demetri Martin on Facebook. I recorded it; watched it. New favorite. He's been around for awhile...I'm just new.
The show comes on Comedy Central...Wednesday nights...10:30 EST. Try it on for size :).
P.S. I have his stand-up CD (iTunes). Outside of the fact that he says the "r" word a million times (or at all), I love what I've heard so far.