Cambond via Amazon offers its Cambond Portable Indoor Wireless Bluetooth Speaker in Black or Blue for $19.99. Coupon code "8E8RVEKK" cuts that to $15.99. Plus, Prime members bag free shipping. (Non-members can spend $49 or more to qualify for free shipping; otherwise, shipping costs $6.51.) That's $24 off and the lowest total price we could find. This 2-watt speaker features a built-in microphone, microUSB, 3.5mm auxiliary port, and rechargeable Li-ion battery with up to seven hours of playtime per charge.