A United States Currency $20 bill was printed in 1996 with a Del Monte fruit stick on it.
The bill in genuine and somehow slipped by U.S. Treasury’s inspection process.
I was clued into this by the Atlanta Journal Constitution, but much more information is available on the web. It came up on the paper because the bill is being sold at auction today and tomorrow.
7 January 2006 Update: The note sold for $25,300, 1265 times its face value.
I would imagine there are strict security protocols at the mint (Mint? Bureau of Engraving?) to prevent people from causing erroneous currency and then “cashing in.” If you could make 1,000 times the value of a $100 bill, just by screwing the process a bit, that might be worth it. I wonder what the penalty for that would be if you were caught?