All you people saying it's going to be useful in places like Africa haven't really thought it through.
You've got the basic problem that to be useful the phone needs to be exposed to the sun.
Which means you need to leave the phone on display in the sun, you can't keep it in your pocket!
Most african countries are poor, and full of corruption. If you leave a phone on display it's going to get nicked.
Look at the performance specs,. and you bet your bottom dollar they're going to be overly optimistic as they're published by the phone manufacturer.
You're going to need 1 hour of bright sunshine just be able to get 10 mins talk time use from the phone.
The question is what are the conditions which they measured that performance?
How bright was the sun, and what was the orientation of the phone relative to the sun?
I bet you the solar panel was pointed directly at the sun. The power generated by a solar panel falls off dramatically as the angle becomes more acute. Ideally the panel needs to be pointed directly at the sun.
And how far was the phone from the base station to give a life of 10minutes?
The further the phone is from the base station, the phone uses a higher power output from it's RF transmitter. I'm willing to bet the phone was close to the base station and the transmitter running at low power output.
My mobile has a lithium ion battery rated at 7200mAh, with a big enough panel I reckon I can charge it in perhaps an hour 15 mins, but that's a large surface area of panel and physically impossible to integrate into a phone.
The only use this solar panel charging has for this phone is under the following conditions:
1) You can be sure of bright sunshine
2) The phone is an emergency phone which you use incredibly infrequently.
The question is, even in standby mode, or even when the phone is off, it still sends burst data transmissions to the base station, it's still consuming power, the question, can the solar panels keep the battery topped up?
The partial answer to that question is: No!, if it's kept in a pocket, a glove compartment, in a drawer. Which comes back to the risk of theft if the phone is on display in the open.
If you want a phone for emergency use, which is about all this one is good for, then you might a well get a wind-up one! (if they exist and I doubt they do).
In which case, you might as well get an emergency battery pack like the Freeloader, and charge it up before you leave home, and then use the freeloader to act as an emergency charger to recharge your phone battery).
And if you're going to be in Africa and want a source of power to recharge a mobile phone and other gadgets because there's no electrical supply out in the bush, then you need my invention when I've finished building it. Not a poxy tiny solar panel which is practically useless.