Thanks to shsilver for pointing it out, he's got a good Terry anecdote here and I'll take a moment and include my own.
In 2004 I was in Boston for Noreascon Four and there was a delay was we (I was rooming with "The" Donewitz as I recall, Ira why aren't you on LJ?) checked into our room, so off to the lobby bar we went. Terry was one of the Guests of Honour and sure enough I soon spotted him making his way through the hotel lobby. "Hey Terry" I shouted, and when he looked waved him over. "Let us buy you a drink." He graciously accepted and mentioned he could only stay a moment because he was meeting Mike Resnick to discuss a project. We assured him that we knew Mike by sight and would help keep an eye out for him.
It took the hotel nearly 3 hours to get our room ready, but every few minutes during that time some more luminaries would join our crew and be amused by Terry. Mike had, as I recalled shown up pretty quickly and just decided to go with the flow and stayed with us the whole time.
For me, it was one of the most memorable and enjoyable starts to a Worldcon I'd ever experienced.
So gather round folks, and raise your glasses high!
Cheers to Sir Terry!