Gaiman's posting had this cover image of Aparo on the cover of The Brave and the Bold #124:
I mentioned that when I was a kid my church had dozens of copies of this particular comic that they just gave away.
In the comic, the artist of the comic, Jim Aparo, is in the comic he's writing, and affects and interacts with the story and characters (http://www.livejournal.com/community/scans_daily/727788.html).
I kept this comic for a while, rereading it because the premise was so weird. Thanks to Gaiman's post, I regained this childhood memory, and a copy of the comic is on the way. Thank God for eBay.
Now that I look at this comic as an adult, it hits me how much the Jim Aparo character reminds me of how it feels to write jokes: The jokes break into my office, point guns at me, and force me to write them into reality.