Ocean Technology via Amazon offers Prime members the Unitek Detachable 4-Port USB Charging Station Dock, model no. Y-2187A, for $39.99. Coupon code "23EDFCUN" drops it to $29.99. Plus, Prime members bag free shipping. (Non-members can spend $49 or more to qualify for free shipping; otherwise, shipping costs $7.23.) That's $42 off list and the lowest total price we could find. It charges up to four devices at once, and is compatible with iOS or Android devices. Deal ends October 31.