Well, this started both with my dead xbox and dremeling it in half and when I recently took my ibook apart to take the thermal pad off and replace it with thermal paste (Funny, I thought it would have thermal paste already). Well this failed because I didn't tighten the heat sink on enough with the two adjustable screws. Long story short, I haven't been able to get it back apart to fix it as I lost my key key O_o. I then just had a brilliant idea of using the xbox heatsinks to add cooling and since they already had sticky thermal paste on the bottom, I figured, why not, my laptop sits on my desk all the time anyways. <------ Special note to that, if you plan to be using your laptop other than on a desk most of the time, I would recommend you get a commercial cooling pad or the such that has fans in it and plugs into your usb port. This is just simply a quick and easy mod that's easily removable in the event that you need to move your laptop or go somewhere with it.
Any Macbook is currently under warranty (and a very good warranty, it is!) and uses an entirely different processor. This should not be attempted on a Macbook.