I'm curious to know what power drain powertop is reporting for you all (along with machine, distro, kernel and additional tweaks you are using). Thanks!
I've not played with powertop before, but I've just had a look - quite addictive to try different things and see what the change is
I found that if I have my N140 sitting in an idle state, with firefox running in the background, wireless usb mouse plugged in but not being touched, then the power consumption reported by powertop was ~ 6.4W. If I start moving the mouse around though then it jumps up to ~ 9.7W.
This is on an N140 running Karmic, kernel 2.6.31 and with no real power-saving tweaks just yet.