http://www.snopes.com/military/medal.htm

Hiya Mike, Dave's story of Joe Foss was the one I've heard over and over and like Dave, I thought it was true. Looked it up on Snopes and found there were a combination of problems in the whole encounter. From the Snopes writeup:

...and he carried with him his Medal of Honor, as well as a Medal of Honor commemorative nail file and a dummy bullet which had been made into a key fob.

Thanks for the heads up Mike.