When my son was in high school he got the contract to do the mowing around the businesses in town. They had a large lawn out front of the offices and a bunch of trimming to do all the way around the building. He had two 21" Toro self propelled mowers and hired schoolmates to help for a while, but he wasn't happy with that arrangement.
So he got an old wire spool somewhere, wrapped some rope around it, staked it to the ground in the middle of the lawn, and attached the rope to one of the mowers. Starting in the middle, he fired up the mower and let it go. It unwound the rope as it mowed its way around and around the spool while he did the trimming with the other mower.
The kid is a born engineer + entrepreneur. I wonder where he gets it.
