A few thoughts from a guy who's been messing with photovoltaic solar panels for some time:

First and foremost, I think you should largely ignore the solar part. This is a battery pack designed to be charged by grid-powered chargers/devices. The charging spec's are for PC (at nearly twice the standard USB rate!?!) or more powerful chargers. I suggest you compare it (battery size and cost) with the non-solar rechargers that are available everywhere.

It's odd they wouldn't list more of the hard spec's on the solar aspect. Or maybe not, because they're hardly sexy. If the photo on the web page is to be believed (?!) it's a lithium polymer 5000 mAh battery. The solar charging capability is apparently 200 mA. I'm playing very fast and loose with the math here, but I believe it would take at least 3 days of full 8-hour direct sunlight to recharge this. Assuming ideal conditions. It's a biggish battery and a tiny, tiny panel. So the solar panel is a trickle charger -- still somewhat useful, but don't be fooled into thinking that this is a self-contained off-grid solution; it certainly is not. It may however give you enough juice in a dicey situation to get your phone connected and fire off a few text messages (and get triangulation going if someone's looking for you).

I'm not saying don't buy one; but be realistic about your expectations. Hope this helps.