This may be slightly off the topic

Just spotted this one over dx http://www.dealextreme.com/details.dx/sku.37216. What's interesting is the capacity 4800mah. Not to mention it was around $5(kinda cheap).

It would be great If we can modify this to make portable charger for mobile phones especially N900 by converting the output cable to micro usb and increase the output voltage to 5.5V (according to proporta usb turbocharger 3400 spec).