Here are the three that I own....The first one is my favorite, an early 1930's Socony Mobilgas banner. This one was in such nice shape I had to have it and I'm glad I bought it as I have not seen another for sale since I bought this one.
The next one is the Mobil can banner that came after the version that Advertologist posted above with the Gargoyle and Pegasus shield at the bottom. This is the only one I was able to find a frame for easily!
Lastly, while not in the greatest of shape, I found this large banner at Peotone a couple of years ago outside for $10. I thought it was well worth that price as a nice hanger for the garage someday. I think it's about 10 feet wide but I have it folded up somewhere in storage...much too big to display in my apartment!
Darin