It was a last-minute thing; I found out a little after one in the afternoon that he was speaking at the Tribeca Barnes and Noble (that's in lower Manhattan) at six. I was worried that my mother wouldn't be okay with my going, since we'd planned for me to go with her to pick up my aunt at the airport, but she was actually very excited for me, because she knew what an opportunity it was, and encouraged me to go. So I did.
He talked about a lot of things, including the new Vimes-centric Discworld installment, Snuff--but mostly about his recent experiences visiting strange little places and dealing with Homeland (in)Security. He was soft-spoken and seemed tired but composed. Someone asked him which one of his characters he'd choose to be if he had to pick one, and he said it would be Sam Vimes.
I was an idiot and forgot a camera, but I brought my netbook, and to my great relief the webcam worked fine. Here I am with him. I was so focused on setting up the shot properly that he had to remind me to smile.
I had given up, years ago, on ever getting a chance to meet him. But now I have.