Here's some ideas....though I dont think any one will be willing to do this, here goes: 1) Use a command line that takes off the key board lights (You wont need key lights at day time) when Its night you can use a command line to turn on the key lights again. 2) Use a command line to power down the LCD lights to 80% or so...(20% battery increase) 3) Use a command line to under clock the device by 50 or 100mhz. (Dont think the n900 needs the full 600mhz anyway)...