just yesterday we were on a walk when my dog found, of all things, a 2-liter pet bottle with an old knee sock tied around it and knotted. He is not a toy-playing dog, he is a destroy-everything-immediately dog (
beef bones don't last more than a few hours around here), but he picked that dang thing up and carried it home.
it was probably something some kids had been kicking around over the New Year holiday (this is Brazil after all, anything is eventually a football), and I wouldn't let him chew it til he made any perforations, but as a nice-sized fetch-and-carry toy it was really, surprisingly good!
my dog's other favorite toy, the one i use for training motivation, is a bit of a heavy-duty truck tarp tiedown that we found on the road one day. He'd do anything to play tug with that.
I can spend a hundred smackers on a rubber kong toy or a police grade tug toy, or i can make a sock bottle or use some trash found on the road, go figure.