Turning off Sudden Motion Sensor to save battery

If you're at a desk all the time plug it in

The Sudden motion sensor is actually an Accelerometer which is a passive sensor and so doesn't use your battery.

http://en.wikipedia.org/wiki/Accelerometer (science lesson)

I doubt the SMS is drawing much power... I doubt its even active unless your notebook is falling (and it isnt- its on a desk). try lowering your screen brightness. that'll have a HUGE effect. disabling the SMS may add a minute, maybe not even. you wouldnt notice.

if someone knows about the SMS for certain, feel free to correct me. however, I'm pretty sure the SMS's electrical need is minimal...

The biggest impact I've found on battery life is screen brightness. Crank it down to half and you'll get a LOT more battery life. I've done some non-scientific experimenting with Bluetooth vs USB dongles and the trackpad.... they all seem to use about the same amount of juice... and not nearly as much as screen brightness.