Bushnell Wingman ($149.99)
There are plenty of portable stereo speakers out there that can link to a smartphone via Bluetooth and play music on the course. The Wingman is water-resistant, has a 10-hour battery and a magnet that allows it to be positioned on any metal area for better sound. Its sweetest feature: When a button is pressed on the tiny remote control, the Wingman reduces the music, uses the GPS in the smartphone and calls out the distance to the front, middle and back of the green on the hole being played.