A factory-recertified iRobot Roomba Discovery vacuum cleaning robot with scheduler is just $121.99 at Buy.com. The Roomba machine vacuums your entire house on command, calculating the optimal cleaning path, and when finished, it returns itself to its charger. The Discovery model is even more advanced with dirt detection: when it "discovers" dirtier areas its cleaning intensity increases. The Roomba Scheduler features active dirt response, self-charging home base, an extra-large debris bin, and, of course, scheduled cleaning. Shipping is free, there's no sales tax (except CA, MA, MD, TN), and new Google Checkout users can get a $10 discount for signing up. Though $2 higher than our previous post, this is still the lowest price I've seen for the Discovery and Scheduler.