Ask HN: What toys have turned into tools for you?

I did an experiment for a friend recently to prove that a USB foot pedal could be mapped to Photoshop functions, in order to retrieve his left hand from command-z on his laptop and put it back onto his cintiq. It worked, of course.

Not really have the same need, I have found myself creating keyboard maps for other programs - my foot has muscle memory for Youtube's 10 second fast forward. When I am in consumer mode, I can lean back with my hands bundled up in my hoodie pockets and not freeze them in this 48 degree New England house on winter savings mode.

What are some toys you have that were elevated to tool status? Computers, commute, cozy, craft, doesn't matter.