P3 International Kill-a-Watt Electricity Usage Monitor. It’s said that when American revolutionaries ran out of wadding for their muskets, the Rev. James Caldwell came with a bunch of song books containing the hymns of Isaac Watts to use as wadding instead, telling them, “Give ‘em Watts, boys.”

And that’s just what this Electricity Usage Monitor will do, recording the electricity usage of appliances plugged into it and giving you their wattage. Get it? Get it? Huh? “Watts?” And the only thing cheaper than that joke is the price: the Kill-A-Watt Monitor goes for just under $20! So if you save a Jackson on utilities in a month because of this, it’ll have more than paid for itself! Then you can buy wadding for your muskets!