To power the unit on or off, hold the power button for a few seconds until the LED starts flashing blue. To enter pairing mode, continue to hold the power button after the unit activates until the LED's color starts alternating between red and blue. The instructions indicate that the unit pairs with a four-digit PIN, but my Samsung Galaxy Nexus didn't even require that much.
The unit doesn't feature its own volume control; instead you'll have to adjust the output volume either on your phone or on the car or home audio system accepting the input. You also don't get controls for skipping forward and backward, but tapping the power button momentarily will toggle Play and Pause.
Oddly, Gogroove's Web site features a number of pictures of the BlueGate plugged into the headphone jack of various smartphones, which makes absolutely no sense, because the audio connection is an output not an input.
After pairing, I noticed yet another oddity. The Gogroove BlueGate connected to my phone with both the Bluetooth audio streaming and hands-free calling profiles, despite the fact that it lacks an internal microphone and wouldn't pass through from my headphones' microphone. You'll want to go into your options to disable hands-free unless you want to confuse your callers with the impending silence.
The Gogroove BlueGate's greatest strength is its simplicity. You charge it, plug it in, pair it, and go. It's not much harder to use than a simple 3.5mm analog auxiliary audio cable. However, the unit's physical design, while compact and unobtrusive, could cause problems for some users.
I may have been nitpicking with my complaints about the device's use of a male audio connection, but my complaint about the nonstandard power cable is an important one. Lose that proprietary USB cable and you may as well throw away your $60 Bluetooth adapter.
If you can find it on sale for less than its $59.99 MSRP (at time of this review, I'm seeing prices as low as $34.99), the GoGroove BlueGate is a good option for adding Bluetooth audio streaming to a car stereo, home audio system, or other use where you'll leave the unit plugged in to power indefinitely.
However, for those who want to use the device on the go, such as with headphones, a device like thethat uses a standard Mini-USB connection for power and a simple female audio input will offer much more flexibility for charging the device and potentially better audio quality.