Of course, the real value of the Car Kit is that it is partially solar-powered. According to LG, 2 hours of sun will get you about an hour of talk time, with a maximum talk time of 16 hours. This seems pretty decent, especially if you live in an area with plenty of sunshine and you tend to drive for many miles at a time. If you live in a foggier area, though, this might be more of a challenge. Also, it would probably be better to leave it in your car when parked to really make use of the solar charging, but we don't know if it's wise to leave a gadget such as this in plain view of potential thieves.
You'll have to charge the device the old-fashioned way to get going. The Car Kit comes with a regular AC adapter as well as an in-car charger. We paired the HFB-500 with the Apple iPhone 3G and it worked great. Though callers still thought we sounded as if we're talking from a speakerphone, we could hear each other just fine, perhaps because of the echo cancellation in the device. We even made a few calls to an airline's automated phone system to see if it could recognize our voice, and it did.
Features on the HFB-500 include the typical answer and end calls, mute, call waiting, last number redial, and the capability to connect to two devices simultaneously.