Ebay has a variety... well, 1000's of usb 5 volt output chargers in a huge range of flavours, the main thing to look for is panel output, 80 mah means very slow charging of any type of battery.
The best type I have seen is a small kit form charger from adafruit.com this takes two AA and converts the 3 volt (AA Alkaline batteries) or 2.4 (NiMh rechargeable AA) to 5.2 volt (USB standard) the chip onboard is a very efficient voltage doubler that is then regulated to the 5.2 volt.
I use a flexible solar panel that is about 800 mm x 250 mm, it outputs around 14 volts at 1 amp (1000 mah) this can again be regulated to whatever you want and used to charge AA batteries.
With charging the thing to remember is that the voltage is the more crucial element of the voltage ampage formula, that is to say a 1.2 volt AA charged at 80 mah is slow to charge, the same voltage at 1000 mah is a lot quicker, the battery will only use what it needs to use mah-wise...
most 'smart' AA chargers will wack in about 500-1000 mah thus charging the batteries (lets say 2800 mah AA's, about the best you can get at the mo) in around 2.8 hours. this is assuming an input of 1000 mah at 1.2 volts... (perfect conditions sun-wise), big assumption due to amount of sun on the panel
The beauty of AA's is the ability to join them in series or parallel to make a voltage bank to your own configuration, 10 gives you 12 volts at 2800 mah in series, 1.2 volts at 28000 mah in parallel!
USB is very forgiving, it will take anywhere between 4.8 to 5.6 volts usually, I have 'played' with my Sony 600 touch at 4.8 to 5.0 it will run, 5.1-5.6 it will run and charge.
SO... things to look for:
USB charger- 12 volt cig. socket for car, AA x 2 USB charger, Solar charger with built-in battery and USB output... etc... just search USB charger on Ebay, that will keep you busy for a few hours
remember- larger panel output means faster charging of the internal battery or the USB device you want to charge.
PSP USB charger- the PSP uses the same size plug as the sony readers, there are a few that have usb mini and PSP DC socket on one end and a standard male USB on the other, plug standard into any USB output and the other end into the sony.
As Drmoze states:
mAh are milliamp-hours (milliamps multiplied by hours, not 'per hour')
you can do a 1000 trials and have different charge times each time....
I hope this helps in some little way, and I am sure I will get chastised by those who know different or better...
My system works, I charge laptops, my sony reader and camera batteries while out hiking for anywhere from a weekend to 4 weeks, and am always looking for a lighter alternative.
The next big breakthrough will be lighter batteries with more capacity, watch this space....
If anyone wants more detailed information or pictures dont hesitate to message me, lets keep it on this forum to help others...
Cheers,
Dan.