OK, OK, you've all had your snark at my genuinely emotional original post and my heartfelt subsequent responses...
The show being at a small theater on the outskirts of Weirdowood, Mr. F. Tompkins wandered (very briefly) around the courtyard, as did Ms. Brewster (for a longer time).
I see people whose work I like, under similar circumstances, on a not-infrequent basis. I thought about going up and talking briefly with each of them - I would have praised Mr. Tompkins' under appreciated (really, Simple Machines speller?) work as Saul F. Tompkins and Ms. Brewster's excellent presence in the too-soon-cancelled Andy Richter Controls the Universe.
In the end, I didn't say anything. I'm not particularly shy, and these two don't seem like the type of egotists who would respond absurdly - I'm looking at you, Dick Enberg - but it just didn't seem like The Thing That I Wanted To Do.
Tom gives good advice on this point - if you want to go up and say something, go up at an opportune time, say you appreciate what they do, get out - and perhaps I'll do that next time. I talked to Tom, Jon and Ted Leo (for a longer time) at the Gathering of the FOT, and it was great, but that seemed like a more natural thing.
