I was working in my yard today and heard a bell coming down the street, ringing with a regular rhythm. I'd heard about an old fashioned mobile service but hadn't experienced it until today.
An older gentleman pushing a hand cart with big red wagon wheels offers knife sharpening. He'll also sharpen other types of blades. I've heard that this includes lawn mower blades.
He parks the cart, folds down the seat, and pumps a pedal powered grinding wheel to sharpen your blade while you wait. He did my big kitchen knife for $2, then went on down the street looking for the next customer. That's a great service to have in the neighborhood.