the Macbook Pro, the hottest laptop out there (and not just in terms of the way it looks). But it seems like you'd be stressing your laptop a lot, so I'll suggest some stuff I *need* to use with the Macbook Pro (even at idle... do anything demanding and it's hello barbecued thighs).

I have the Rain Designs iLap for the 17", which is an aluminium plate which dissipates heat and also keeps the laptop clear of the desk / lap.
http://www.raindesigninc.com/ilap.html

I also have the Griffin Elevator, which may or may not be compatible with other laptops (the MBP has a flat bottom and the stand needs that to work). This is a raised stand that you'd use on a desk with a separate keyboard and mouse.
http://www.griffintechnology.com/products/elevator/

You could also try Cooler Master's stuff, which features active cooling (i.e. fans). I believe the Notepal W1 will be a nice snug fit, just 2cm wider than your laptop and almost an exact fit in terms of depth.
http://www.coolermaster.com/products/product.php?act=morecategory&finalflag=Y&tbcate=1&cateid=000016