Honestly, most of the solar gadgets we see aren't terribly practical, and often rely on a primary, wired power source. Not the Nextar NXBT handsfree kits—these are the real thing.
The NXBT is modest in its goals, serving as a no-frills Bluetooth handsfree kit for your car. It offers a simple caller ID interface as an upgrade, boasts either 150/6 or 250/10 hours of standby/talk time depending on the model, and recharges its batteries by just sittin' on your dash, soakin' up some rays, or something.
The point is, this device will probably succeed because of its plainness. Too many solar-powered gadgets use the tech as a gimmicky augmentation, or an impractical addition that renders the device useless for days at a time. The Nextar NXBT will sit in one of the sunniest places it could, perform one valuable function for a reasonable amount of time, and—with any luck—perform it well. The NXBT-001, with the lower talk time and no caller ID, will ship in Spring for $60, while the upgraded NXBT-002 will go for $70. Both will be on display at CES 2009. [Nextar]