I have a Toshiba Tecra M4, and while I love the machine, its fan can get really load (with people starting to look at me :) )
Thanks to Jan, I now have a little tool I'm running on Vista which reduced the heat a lot on my machine, while keeping performance high:
Check it out! http://weblogs.asp.net/jan/archive/2006/06/12/Reducing-Fan-Noise-on-my-Tecra-M4.aspx