The unmanned lawnmower is nothing new, but we still think there's something downright iffy about arming a Roomba with sharp metal blades. That said, if you've been dying to get in on the action, SmartMow might be worth checking out. Set to hit the stores in Spring '09 for $749 (much cheaper than some otherrobo-mowers), the thing weighs 17 pounds, features three cutting blades, will cut around a sixth of an acre on a single charge (about 2-3 hours), and is auto-docking. As far as knowing where to mow, SmartMow eschews sci-fi grass detection algorithms and rudimentary artificial intelligence in favor of the tried but true method of marking off your mowable yard with an edge wire. The best thing about the bot, however, may be its educational value -- not only will it teach your kids about robotics, it will also show them how people with money can buy their way out of doing chores. Video after the break.