This gizmo lets you know if the washing machine is leaking or overflowing before the damage is done. A sensor rests on the floor and sets off an alarm when water touches it. Sonin makes two types: one with a regular alarm (model No. 00700, $13) and another that works like a baby monitor, with a receiver, in case you are out of earshot (model No. 03300, $30). Call 800-223-7511 for store locations.