I'm glad you got to see GRRM. I too saw him shortly after a Feast for Crows came out. It was in the Village in Manhattan.
It was in either a B&N or a Borders (forget which), in the thinnest bookstore I've ever been; from the street, it was probably only like 10-15 meters wide, but it was very deep. The line snaked around through just about every book section in the store, both levels.
I mention this because there was no way to actually see him when he did his pre-signing reading. I think i was standing between two steps next to the art books section, craning my neck to hear better. Sure, it was kind of disappointing at first, but he has this way about him ... i would have been happy hearing him read stuff he wrote that day if i was in a janitor's closet. It was just pitch perfect.
There's no way to describe it other to say that he truly loves his fans. You could tell from the smile on his face, the way it traveled to every person leaving the line with their signed book.
When i got closer to him, he had a slip where we could write our names and what we wanted him to write. They also had stickers at the door if you wanted to bring your own book in instead of buying one there, but we were so early that somehow i didn't get one and freaked out a little. The bookstore people were nice about it and just gave me a sticker. I guess i didn't look the sort who would steal books or ask cutting questions about sports.
I was a little afraid of talking to him, with the Jordan thing and all, but he asked me where i was from, and what i did, and was just a sweet man. My friend who was a new reader of his (and this was his first signing) asked him to put something irreverant/funny in his book, and Martin laughed it up and complied. Despite the line and everything, he gave us 2 minutes of conversation. He realized it was far from Philadelphia and really appreciated us coming there. It was the sort of thing that made me grin stupidly down the road when HBO greenlit him, I was just so happy for him.
This is clearly tangential and I apologize (censor if you'd like), but Philly's mass transit (SEPTA) does not run 24 hours a day, and we got stuck overnight in Trenton, NJ (top ten murder city - but surprisingly few homeless) coming back.
Still, the stars shone bright that night (even over Trenton); i wont forget it.
Top of my author signing wishlist right now is Rothfuss... he just seems fun and nerdcool. Like someone I'd run into at PAX East or Otokon. PLZCMETOPHILLYPAT!