I worked with him once, on the movie Dogma. I worked in the locations department, and we shared an office with the Teamsters, who were all big George Carlin fans. Consequently, he spent more time in our office than any of the other actors in the film.
It's been too many years (ten?) since our first meeting for me to recall exactly what he said, but I remember distinctly that he made a real effort to include me in the conversation (in a roomful of Teamsters, it's easy for the locations chick to be left out), and that he was full of jokes -- not of the doing-a-schtick variety, but more of the making-everyone-feel-at-ease sort. You know -- it was Bill Murray, who wanted to see everyone have a good time, versus Chevy Chase, who wanted everyone to see how clever he was.
I guess the moral of my story is that while I didn't know him well, I did know George Carlin to be a really warm and funny guy, and it thoroughly sucks ass that he's gone. So, in honor of his passing:
Shit, Piss, Fuck, Cunt, CockSucker, MotherFucker, and Tits!