Here is a picture of the D battery pack I was talking about, it will run the pictured phone and Palm Pilot.

If you don’t know how to make one of these, any TV repair shop guy can make it for you. or e-mail me and I may be able to talk you through it. The D battery holder (Also these battery holders come in C & AA size batteries if space is important) is less then $3.00 at any Radio Shack. With it, a car charger and a soldering iron and some hot melt glue you will be able to run anything electronic for months.