A lawnmower, similar in function to a Roomba, that runs around the yard and cuts the lawn... or at least pretends to cut it.
LASER-guided and largely harmless, it just skims a bit off the long ends and deposits a pile of lawn clippings at the back steps each day, without scalping the lawn or chopping up the tennis balls and sundry tools and shit the kids leave lying about.-- UnaBubba, Jul 13 2012random, halfbakery