Probably not, but it also won't really do anything to help it. Those laptop cooling pads are pretty much a scam. They only bleed off heat from the bottom of the unit, and if we remember our basic high school chemistry/physics, hot air is less dense than cold air, so it rises. What good does bleeding off a little residual heat from the bottom accomplish? Not to mention most of those are powered by the USB hub of the laptop itself, so that means the laptop has to draw in more power to feed that, and if we remember some of the basics of thermodynamics, the final stage of any energy is heat, and most machines never even approach 100% efficiency, even if 100% efficiency were possible.
So even if we assume that the laptop PSU is 80% efficient across the board (which is unlikely), if say the fan needs 5W of power to run, in order to deliver that 5W of power, the PSU has to draw an additional 20%, or 6W. That additional 1W of power being converted into heat. And let's not forget that the average PSU is really only 60-70% efficient most of the time. Even the 80 Plus certification program only mandates that PSUs be 80% efficient at 20%, 50%, and 100% loads. Anything between any of those values is fair game.
The finally we get to the part where Sony designed the PS3 to be run for extended periods of time and have adequate cooling. So unless you're running it in an unusually warm location, in which case convectional cooling probably wouldn't be enough anyway, the cooling pad should be superfluous.