I was mowing a regular client's lawn last year and his new neighbor (house had been empty for quite sometime) walked over and asked how much I would charge to mow his lawn, ride only, no trim. It was about 6 inches high and he wanted me to mow it as low as possible. Keep in mind now, this is not the customer that cares about his lawn, he just didn't have anything to knock it down with. I told him it would look bad but that is what he wanted. So, i told him how much, took me all of about 15 minutes because if he didn't care how it looked when I was done, I sure as hell didn't. During the mowing, I'm going along and WHAM!!! out of the chute flies a fiberglass handle off of a claw hammer. I just knew I'd tore something up. I also saw a peice of plate steel about 4" by 6" and 1/4 inch thick in a spot I had already mowed. I'm glad I didn't suck that up. I never found the hammer head but took him the handle and said "I found your hammer" He appoligized and said one of his grandkids must have left it out there. Ruined a brand new set of blades. They costed as much as I charged him to mow it. He asked me again later to mow it and I told him not unless you walk around and pick up everything.