I mentioned on the show that there was a firmware update for MacBooks and MacBook Pro notebooks that will aid the overheating/spontaneous shutdown problems some users of those models are experiencing. You can get that one from Apple by following one link in the article linked to above.
Tony Smith has posted a short piece on The Register's site detailing how to further adjust the thermal output of your MacBook or MacBook Pro using third party software (and freeware at that!) to control the speed settings of both cooling fans. (Especially the minimum speeds of said fans.) It is an easy read and will tell you absolutely all you need to know, except for mentioning that there are several more pieces of software to do the job besides the one he mentions.