Even without GreenPlug, there has been significant movement over the past few years toward the acceptance of the mini-USB port as a connection standard for portable devices. Sony, for example, now offers USB charging on devices such as the PSP and Sony eReader, where others previously required proprietary adapters. The USB Implementers' Forum is working on new guidelines to ensure better compatibility for chargers and devices using the popular port that was designed first for data transfer. And there is now legislation in place in China that mandates that any phone sold there must enable USB charging.
However, USB has limits in terms of the wattage that it can deliver and can't charge, for example, notebook PCs, as well as many camcorders, digital cameras, and other products. Nonetheless, in a nod to the growing momentum around the USB connector for cell phones and other low-power gizmos, GreenPlug has designed its connector to resemble a mini-USB port. A GreenPlug adapter can charge mini-USB products that don't have its chip, even though it won't offer power-saving benefits in that circumstance.