Ok, so every now and again in my research I find a series of strips that make me burst out laughing in the library (and cause me to get a stern glare from the librarian...)
This is from Episode 68 "Koffee with the Kents" from the 1951 daily strip.
The gist of it is, during the episode, Superman is booked on Lois and Clark's morning radio show (go with me...they are married, and have a radio show). So in he comes, and sits down next to Clark Kent.
Cut to the outside world, and a newspaper strip reader is confused as to how Superman is shown in the same panel as Clark Kent. So naturally he heads over to Wayne Boring's studio to have him explain it.
So Boring decides it'd be simpler for Superman to explain it to him, and he calls him in (evidently he's been using him as a model to make his drawings more accurate....seriously...it says that). In order to convince the man that he is real, Superman proceeds to trash Wayne Boring's studio.
Anyhow, these are just a few strips from this storyline, but I bet it was as fun to create as it was to read