Para compara camaras digitales, http://dxomark.com/index.php/eng/DxOMark-Sensor
La Nikon D5000 esta muy bien en precio/performance.

Laptop batteries all use a standard cell which is slightly larger than AA. What you need are unprotected 18650 Li-Ion cells. You can find made in China cells for $3/ea from places like DealExtreme.

Como controlar la velocidad del CPU

http://www.pbus-167.com/nhc/nhc.htm