One thing that Leopard has done for me is that it got me experimenting with using reduced processor speed in the Energy Saver Preference panel to try and keep my PowerBook's raucous cooling fans quiet. It's an almost absurdly simple workaround, and it works pretty well. It's not all sweetness and light, however. Email performance (at least on dial-up) is still big-time horrible in Leopard..... and no Windowshade X on the horizon yet

	Read more at AppleLinks
	www.applelinks.com/index.php/more/keeping_temperatures_down_with_leopard_and_tiger_os_x_odyssey_901/