Would this homemade solar phone charger work for the iPhone 4?

There's this great instructable on how to make a solar phone charger (if you're interested, it can be found here: http://www.instructables.com/id/Solar-7-up-Solar-phone-charger-in-a-bottle/)

But basically it uses a solar panel, which is plugged into a 3.7V 2000mAh LiPo battery, and then plugged into LiPo Rider Pro (which is apparently a charge regulator and also steps up the voltage to 5V which is the required voltage for USBs). I THINK this is how it goes… The instructable is a bit unclear when it gets to plugging into the LiPo Rider Pro; if anyone's nice enough to actually look through the instructable - it's fairly short - and explain it to me a bit better, I'd be super grateful.
Anyways, a male to female USB cable is plugged into the LiPo Rider Pro and then you can use your iPhone USB charger to plug into the male to female USB cable to charge your phone via the LiPo battery (which is charged from the sun).

So my question is, do you think this works for the iPhone 4? Because the instructable doesn't specify, and in the picture, I can't tell if it's an iPhone 3G or 3GS but if it's a 3G then there's a bigger chance that it won't work for the iPhone 4; I just want to make sure it'll work for my phone before I go and buy the required materials.

The LiPo Rider Pro part is really confusing for me… I read the product wiki for it and it didn't help at all; doesn't show how to use it or anything, and there are no detailed/helpful explanations. My knowledge on electronics is really limited, but I've really been trying to understand everything; I've spent my entire spring break researching and finding out about batteries and voltage, but there doesn't seem to be any good answers to the specific questions I have (at least, not in the places I've looked online… I've honestly googled for hours). I really hope someone can help, thanks so much in advance to any who answer.

Yes it will work. It won't provide as much/fast as a charge as a wall charger but it will certainly do the trick.

From what I have read those solar chargers will work but they charge really slow. Great if you are out camping or hiking, etc, and have the time to let the charger sit in the sun all day, as it provides a way to always be able to recharge iphone or ipod.