Working Assets, a San Francisco wireless carrier with 50,000 subscribers, has a “carbon-neutral phone” program that has the company paying $55 to the Carbon Fund for a year’s worth of carbon offsets when new subscribers sign up for a year, Bits reports. 

The company’s latest product is a solar-powered phone charger being released today. The company says it is the first solar-powered charger for the mobile phone market in the U.S.