Devices to disable to extend battery life, with estimates

[simms]

1) Bluetooth (+?)
2) Wifi (+20 minutes, maybe?)
3) Lower screen brightness (+1 hour)
4) IR (+10 minutes, maybe?)
5) Defrag often (+?)
6) Reduce screen resolution (People like their resolutions so it's unlikely!) (+?)
7) Reduce screen colour resolution (12-bit, 24-bit, 36-bit) (+?)

Possible other entries...
Ethernet?
9) Modem?
10) Serial?

Now I've heard disabling Ethernet and Modem (as required) actually increases your battery life. How would disabling them work if nothing is plugged into them? Is that also the case with the serial port?

[simms]

I came up with a few more...
11) Installing POWERPLAY on your ATI card
12) Using NHC or RMClock to clock down the voltages for Speedstep.