Last time I heard (which was about 2001, frankly, because a dude drove a convoy of trolleys into my scooter and I went to report it to the shopping centre management) a cartpoke was referred to around these parts as a trolley return service operator.
Instead of lowing, the carts could squeak their wheels. Some of them could get angsty and rear up on their hind wheels. ... Do you think the cartpokes would sing to the carts to calm them? And fire their barcode-scanner guns in the air as they ride into town behind the herd?
I mean, think about the cartpokes in their little Target baseball caps and reflective vests, driving the carts down the trail, far behind a golf-cart-driving guy named "Cookie" who drives ahead every morning to find a good camping spot and cooks beans. They cartpokes use cattle dogs to help keep the stragglers in line. Maybe they ride Segways. The carts cross rivers, and when they get nervous, like before thunderstorms, they could stampede. The carts lose some weight on the trail, so they have to be fattened up before sale, or they turn into hand-baskets, which bring a lower price.
This seems like the best word for describing those people whose job it is to drive shopping carts back into stores from parking lots. (See also cowpoke. Another possibility is cartpunch.) This thought made me, for the first time in my life, want to make a short film.