Ends up used/useful for something else (other than intended use). . .

I'm always a little surprised how many times I'll design on something and it ends up used for something else.
For example: Digital organ amp (very sturdy)? Rockin out concerts on a beach in Georgia instead. Energy efficient heat system? Waterproof electronic draft barrier (temp leveling, not main heat, and survived several floods with no errors). The list is probably a lot longer; however, those two are the most offensive, and accidentally the most glorious too.
Oh well! Feel free to add to this list with yours. . .
I'd like to hear about it.