So I was casually reading an article on CNet news last night, and all of a sudden I could hear the fan in my laptop go to full speed. To my surprise, even though I was just reading static text, some Flash applet that wasn't even in view was running my CPU at full throttle.
I have one of those Kill-a-watt devices you can plug things into to see how many power is consumed. My Macbook typically draws about 20 watts when I'm just surfing the web (it drops to less than 2 watts when it goes to sleep). As a test, I tested the consumption when sitting on the web page, and my laptop was drawing 45 watts. That's about what the laptop draws when I'm watching full screen HD quality television on my laptop.
I went to CNN.com's website, and sitting on a random article with a Flash banner ad consumes 27 watts. Sitting on the same page without the ad consumed 20 watts.
Fortunately, there is a FireFox addon to disable Flash. You can even put a button in your toolbar toggle it on/off at will, which is convenient in the rare case that you do want to see a flash animation.
http://flashblock.mozdev.org/
The power consumption aside, flash ads are annoying and it's actually kind of nice to not see them.
