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I got a really nifty gadget called a Kill-A-Watt recently because it was on Slickdeals and Jeff Atwood has discussed it in the past. I am basically copying what he did in this post here.

Normal use (before testing anything: 12w

Baseline power usage (everything turn-offable turned off, minimal CPU usage) 6.5w *

LCD brightness

min:	7w
max:	8w

SSD

copying large file: 7.5w *

wifi

baseline	6.5w
on but disabled:	8w
on, connected, idle:	8w
on, connected, downloading:	8.5w *

takeaway: disabling the wifi through nm-applet does nothing; turning it off with eee-control saves 1.5w

webcam:

baseline:	6.5w
on:	7w
in use:	9w

cpu: I did $cat /dev/urandom > /dev/null. Not sure if this is a legit way to test CPU usage, but it brought the CPU to 100% *shrug*.

baseline:	6.5w
powersave:	8w
normal:	10w
performance:	10w

These CPU throttling levels ("powersave", "normal", and "performance") were used in some built in program in the stock install of Linux. Now that I'm running Ubuntu, I can ostensibly get them from eee-control, although since "normal" and "performace" use the same amount of power I'm not sure if eee-control is actually accessing the same settings.

* The device doesn't actually have this precision. When I say x.5, I really mean it was flipping back and forth somewhat randomly between x and x+1.

Here's a graph!