I know this might sound like an overkill, but I actually have a small fan on my desk blowing air into the fan exhausts at the back of my ASUS N50V whenever I play video-games (The laptop cooling pad is not enough) which works fine for me.
You should still look into the solutions mentioned before (clean the fans and vents, thermal paste) but having a small external fan helps a lot. Not very portable though.
so you're blowing air in reverse of what the cooling system is doing. That's not a great idea because you're creating back pressure and the fan motors see increased load