I only ever met him once that I can recall. (Though I guess I shouldn't say it quite that way, as it makes it sound as if he's no longer with us—but he's still quite alive!) It was on September 26, 1971 in Central Park.
The Newspaper Comics Council of New York and the New York Daily News co-sponsored a 75th anniversary celebration for the comic strip. (I assume they were counting from the year Richard F. Outcault's Yellow Kid first appeared in the New York Journal American.) It took place at the Bandshell, and many other cartoonists were there in addition to Barry, including Mort Walker, Tex Blaisdell, Irwin Hasen, and Bill Kresse.
I (you know me) tried to finagle as many sketches as I could. Here's Barry's, which you can click to view at a larger size.
The event was covered in the Daily News, which devoted its center spread to it the following day. No picture of Barry there, I'm afraid, though I can be spotted in the crowd. I'll naturally (what did you expect?) inflict that photo on you someday.
But meanwhile—happy 82nd birthday, Sy Barry!