Mozart's backside
Mozart's buttocks were so tired after a 1771 coach ride to Vienna he couldn't ride on. Had a da Vinci prize advanced spring technology earlier, Mozart's coach might have had a smoother suspension—ie the prize might prove useful in unexpected way.
The Loebner Argument
"When Mozart rode to Vienna in 1781 he wrote 'I rode the mail coach as far as Unterberg, but by that time my backside and its surrounding parts were so sore that I could endure it no longer.' His discomfort was a result, I must suppose, in part from poor suspension of the coach...Suppose a concerted effort had been made early, to fly using springs. Perhaps the concepts of stress and strain would have been invented sooner, along with advances in in spring technology that would have been a boon to humanity and Mozart's buttocks. There is probably still room for improvements in springs" (Loebner, 1994, p. 80).
"Research would be boring, indeed, if every effort resulted in answers only to the question or problem intended. Perhaps my prize will not lead down the straightest path to AI. It will prove useful, nonetheless, perhaps in very unexpected ways" (Loebner, 1994, p. 80).
Source: Loebner, Hugh (1994). "In Response." Communications of the ACM, 37:6.