It's coming out in August! But you need to be in Japan. :-( The Solar Hybrid 936SH, is by Sharp for SoftBank mobile. It has a big solar array up front that'll give you one minute of call time or two hours of standby per 10 minutes of charging. It also has IPX7 water resistance, an 8 megapixel camera, and a full wide VGA display.
Solar and ruggedness go well together. If you're outdoors hiking and in low signal areas, your battery will burn down quicker, and as there aren't any 100V sockets on El Capitan last time I looked, being able to recharge that battery just with the sun makes a whole load of sense. I predict it'll be in the US late 2010.