The wood floors constantly show dust and hair and crumbs. These things are easier to ignore when they're on carpet. I've been using a broom for the past 4 years or so but I've always been curious about the Roomba robots. Michelle wielded a 20% coupon at Bed Bath and Beyond and we got one. It's a curious little creature, and it's much quieter on carpet than it is on hardwoods.
Check out this video of it in action.