AAA powered Arduino
If you are interesting Arduino projects.this is one that cool design.Funax is MAKE Flickr Pool member he made an Arduino-compatible board powered by a single AAA battery. In the circuit he used step-up converter circuit to boost the battery’s 1.5V output to 5V and meet Arduino’s minimum power requirements. Keep in mind - this circuit would considerably reduce current supplied to the board and therefore limit its ability to power external components.
   AAA powered Arduino
Visit AAA powered Arduino website
www.flickr.com