I always liked this one...
Q "Why does the new Italian Navy have glass bottom boats?"
A "So they can see the old Italian Navy"
That reminds me of the one about the cache of WW2-era French rifles that were recently discovered and put up for sale. They're in remarkably good condition, never been fired and only dropped once!

another one, dumb and slightly risque...
Q. What's the difference between a clever midget and a girl with V.D.?
A. Well, one's a cunning runt...