Logitech offers a free Logitech Bluebooth Speaker Adapter, model no. 980-000540, with the purchase of select computer speakers. It's the best such giveaway offer we've seen from Logitech, with most bundles at the lowest total price we could find. This device allows you to pair up a Bluetooth enabled audio device, such as a smart phone or tablet, with almost any pair of powered speakers. Deal ends September 30.

A best bet is the Logitech Z506 5.1-Channel Surround Sound Speaker System (pictured), model no. 980-000430, for $99.99. With the Bluetooth adapter and free shipping, that's the lowest total price we could find if purchased seperately elsewhere by $20. Features include 75 watts RMS of total power, down-firing subwoofer, 45Hz to 20KHz frequency response, 3.5mm audio input, and more.