i've met the man twice in san francisco, briefly each time.
he was neither pissy nor pissing himself with joy. he seemed a tad robotic and preoccupied when signing stuff. but then again, i guess you would be if you had stuff shoved in your face all the time to be signed, and you don't really like signing things to begin with.
my boyfriend argues that it goes with the territory. some rockstars choose to keep their public and private personas very separate. neil, on the other hand, has always played the fan interaction card - he talks to people during shows and webcasts. he gets people to respond to him in kind. so he sort of has an "obligation" to be nice.
it's one thing to say, "neil got pissed at me because i waited outside his house for him" and another to say "neil didn't seem to happy after the show, but i asked him to sign something anyway."
i remember during the fillmore gig in sf (july 7) i was standing next to a girl who seemed a bit upset. i asked her about it and she said that she'd met neil just before he went into sound check and handed him a book she'd made for him. his response was not what she'd expected. he sort of dryly took the book from her and thanked her before walking off. however, he did take time out later during the gig to acknowledge her book and the people involved. she was pretty happy with that.
i've had a couple of things signed, and had a photo taken with him. but i think this next time i'll lay low and just hand him a small gift.