I bought this as I liked the idea of being able to power my mobile phone from solar power. I'm still not sure that this is 100% possible especially once I get to winter months in the UK however I've just spent a week in Cornwall in June and managed to not charge the phone conventially all week.
Initially I thought that the battery might be faulty as after a day in the sun the phone only charged for a few mins before the battery was dead. However this went away after some prolonged days of charging. If you're buying this product I suggest leaving the battery on a mains charge overnight the 1s time. I've had to do this with other rechargable products in the past but didn't think of this until afterwards as the instructions provided are quite limited.
During my week away I was leaving the pack in the window overnight so that by the time I was leaving the house it had had a few hours of morning sun. With some more time later in the day spent charging provided around 45mins - 1 hour of charging for my nokia 5800 smart phone.
The bag itself is also quite smart looking and certainly a talking point. Storage not massive but certainly good enough for an overnight bag/carry on for a plane.