I never remember to charge my Bluetooth headset, which is bad because I drive around Washington, DC a lot, where it's illegal to talk on a cell phone while driving, unless you're using it hands-free. The Sun Bluetooth headset by Igua is the first solar-powered headset on the market. Fully charged, it provides in darkness 9 hours of talk time and 200 hours of standby time, and in indirect sunlight 12 hours of talk time. It also comes with a USB charging cable. So long as it stays in my ear, it seems like a very simple solution to me, especially for travel.

Priced around $90 to $100 from U.S. merchants such as BetterBuyElectronics and DS Miller (though seems to be mostly sold out or on backorder at online shops).

Via textually.org.