Funny with the external charger IE solar and such, i have just remade a ciruit from 2x circuit i bought of EBAY to make a "travel" charger from some of the many lithium battery's i have laying around.
Will ad this little charger on my phone mod thread soon.
The little circuit puts out 900mA because it's of the 500mAh circuit's joined together + a 100ohm resistor on the data pins on the USB, the resistor limits the output to 900mA.