Retractable Power Cord
Yes, this is a small innovation, but an important one. If you've ever gotten exasperated when corralling a long vacuum cleaner cord, looping it around those hooked posts, straightening it when it gets kinked or rescuing it from under the beater brush, a cord that will retract into the vacuum with the slightest tug is almost as nice as having a dog that actually stops barking on command. Don't expect this feature on all vacuums, though. It's more common on canister vacuums than on uprights. Oh, and if you want the most versatile retractable, look for models with 30-foot cords instead of the puny 20-foot lengths. That way you'll be able to get all the way down the hall and into the small bedroom without having to switch outlets.