Bluetune-Solo ($50) is a small monaural Bluetooth speaker with speakerphone capabilities, released by Shenzhen-based Divoom. The tube-shaped handheld unit includes a rechargeable battery, powered through Micro-USB with the included cable. That cord can also be used to daisy-chain multiple speakers together for enhanced sound. Five colors are available, each with a soft-touch chassis capped by silver metallic top and bottom pieces; we noticed pretty…