If you're waiting for the subway in New York City, and you drop something on the tracks, you can call a "Lost Items Retriever" to get it back for you. It happens all the time, and this short video shows a few retrievals on July 1, 2014. They use grabby-tongs (my technical term) to pick up the items and return them to the booth. Enjoy:
You can read more about the process in Amy K. Nelson's article for ANIMAL. One tidbit: "[I]n 2013, their office alone fielded 9,239 calls." And I didn't even know this was a thing!