] Moth found trapped between points at Relay # 70, Panel F,
] of the Mark II Aiken Relay Calculator while it was being
] tested at Harvard University, 9 September 1945. The
] operators affixed the moth to the computer log, with the
] entry: "First actual case of bug being found". They put
] out the word that they had "debugged" the machine, thus
] introducing the term "debugging a computer program".

There's a pic on this page with the actual moth taped into the journal. Though I'm not convinced that this is where the term bug or debugging came from. It sounds like the term was already in use, and then when they found this moth, they taped it in as a joke since they'd actually "found" a bug. Still, it's a great story. :)

First computer bug?