Amazing Bike Lawn Mowers, article by Warren McLaren on Treehugger. Too funny. I believe that when I saw one of these in some old friends yard ( you know who you are), it was called, A Redneck Lawnmower.
Pick up loose screws & nails in seconds, minus the dust. Screw a pot magnet (at most home centers) on the end of a wood dowel to create your “picker-upper.”Place an inside-out sandwich bag over the magnet and start sweeping the area.