Seinfeld & Superman

I'm sitting here watching a Seinfeld re-run and for some reason I faintly remember reading years ago that every episode references Superman in some way. I really can't find the reference while watching. Do any of you know what the references are? Or do I remember it wrong? I've been looking on his walls, furniture, clothes, and listening to the dialouge, but I just can't find it. I could google it, but I'd rather see if any of you know where the references are. If you know let me know by commenting to this post.