The OLPC XO laptop [1] is considered to be one of the most green of machines when it comes to sustainable computing. Of course, sustainable computing does not only mean green, but being green or small-environmental-footprint is a major component. How do computers run with as efficient a footprint as possible? In the following video, Dr. Mary Lou Jepson [2], the ex-CTO of OLPC explains how she got the XO to be a green machine.

Even more important though, is that fact that engineers are currently working hard on a very aggressive suspend-and-resume [3] regimen for the XO laptop where the laptop will be able to suspend and resume on the boundaries of human perception (100 milliseconds or so). The idea being that the computer can remain suspended while you read the contents of a web page (the display is wired separately, so it still displays when the motherboard goes to sleep). That saves power and could effectively increase the runtime to 10 hours per charge. Of course, I am speculating the 10 hour benchmark, but that is the goal; 8 1/2 to 10 hours on one charge. The better part of this scheme is that some day, in the near future, my Sony VAIO running Ubuntu will be able to benefit from this work (FOSS) and will suspend (which it does today) and resume (which it does not) so that I can actually get something like 4+ hours out of my 7 1/2 hour Sony battery.