Martha Simmons wrote:Now, am I right that Paul's post means that a 70 kg rider can output almost 10 times more power than his laptop consumes? 
Yes, I'd say so. 25 W is not that much.
An interesting experiment might be to plug the switched-off laptop with empty battery to the kill-a-watt device, to see how much power is used when charging the battery. And then measure how long it takes until the battery is charged. These would probably be the conditions a rider would experience when recharging the battery, as I don't think the idea was to use the computer while riding.