Pictures of the Li-ion charger prototype are at http://tinyurl.com/yfs3ws3
The charger board and a battery are mounted underneath the NB2A microcontroller
board. The 3V3 output of the charger board is connected to the external power
input of the NB2A. The 3V3 output can run off of the USB 5V, the wall adapter
or the battery. Pictures of the NB2A + charger are at Loading...
(* jcl *)
www: http://www.wiblocks.com
twitter: http://twitter.com/wiblocks
blog: http://luciani.org
Nice. Does your charger have a battery disconnect to prevent over discharging of the battery when the battery is powering the system?
I destroyed an expensive R/C type Li battery several years ago just by forgetting it was on, powering a small 20ma display device. 
Lefty
I do not have a battery disconnect. The battery is connected directly to the low
dropout regulator.
The batteries I plan on using have a discharge cutoff built on the control
PCB that is in the battery assembly. IIRC the discharge cutoff is in the 2.5V - 2.75V
range.
(* jcl *)
www: http://www.wiblocks.com
twitter: http://twitter.com/wiblocks
blog: http://luciani.org