Here's one of those accessory ideas that you wish you had thought of. Jon Liow of Designed by m was tired of hearing his laptop fan kicking in when he was working on something (not that it would ever happen with a MacBook Pro...), and tried a lot of different solutions. The CURB (pre-order price of US$12.99) is essentially a bumper that holds up the laptop in one of two positions and allows a recharging cable to sneak through as well.
The idea is to raise your laptop just enough that air can flow all around it to keep things running cool. It's made of 100 percent food-grade silicone, in case you wish to use it as an eating utensil as well. I suppose you could cut a $1 foam pool noodle to shape to get the same effect, but it's just not as classy looking.