I remember seeing the fellow in a few movies, too. He was one of those legends who people knew even if they never saw his show.
One of my favorite bits with him was an infamous on-the-air practical joke that was played on him. He was talking to the viewers when he heard a scream coming from backstage. While still on camera he went to the back of the set to see what happened, opened a door, and just off camera was a topless stripper shaking her thing. Since this was not only a) live TV but b) a kid's show, Sales had to try and recover while still on the air (the dancer of course wasn't seen on TV though someone had a second non-broadcasting camera set up to record her). It was a great bit of TV even if the viewers had no idea what just happened. Apparently it was a gag pulled for his birthday.
You can see the joke play out on YouTube. There's a clip that shows what the viewers saw, followed by the uncensored in-house version. Since that version has nudity and is NSFW I'm probably not allowed to post a direct link, so just do a YouTube search for "soupy sales- lunch with soupy sales, 1959".
Great stuff! RIP Soupy...
Alex