CowBoom offers the Powermat Portable Charging Mat in Black, model no. PMM-PT100, for $14.99 plus $5 for shipping. That's $5 under our mention from two weeks ago and the lowest total price we could find by $25. Sales tax is added where applicable. This mat wirelessly charges up to three Powermat-enabled devices and includes a universal powercube with eight tips for charging other electronics.