Ever find yourself with a water-soaked low-battery phone? Sharp and Japanese network KDDI have a solution: the world’s first solar-powered waterproof cell phone. The phone, scheduled for a June release in Japan, can nab one minute of talk time or two hours of standby power from ten minutes of sun. The phone can derive 80% of its charge in total from solar power. It’s not a fast enough charging time to change anyone’s life, but it’s ideal for afternoons in the park or on the beach.

Details on Sharp’s phone are scant, with pricing yet to be released. The company hasn’t given a timeline on when the phone will be unveiled in the U.S., but Sharp’s cell phone will beat both Samsung and LG’s solar-powered models to market.

Samsung’s Blue Earth phone is made from recycled plastic bottles and features a built-in pedometer that calculates savings on carbon emissions from walking versus driving in a car. The phone will be released in the U.K. some time during the second half of 2009. LG’s solar model works a bit faster than Sharp’s–10 minutes of sunlight provides enough power for three minutes of talk time–but the company hasn’t yet hinted at a release date. The most exciting development in sustainable cell phones may not be solar at all. Kyocera’s kinetic energy-powered concept phone features a fold-out OLED screen that’s big enough for movie-watching.

Related: Samsung’s Blue Earth is First Solar-Powered All-Touchscreen Cellphone

[Via TechRadar]