If you think flash on websites are annoying and is putting pressure to your cpu, you can download an add-on to Firefox or just uninstall flash.

Uninstall Flash

Flashblock - Flashblock is an extension for the Mozilla, Firefox, and Netscape browsers and blocks all flash content from loading. Easy to see a single flash with a click, if you change your mind.
Blocks following content types:
* Macromedia Flash
* Macromedia Shockwave
* Macromedia Authorware