This is a potential warranty voider, but some folks on Instructables have put together some instructions for cleaning the dusty insides of you laptop, which should extend its life.
Then again, if you break the laptop, the point is sort of moot. If your laptop is experiencing overheating issues, however, it might well be worth the risk and the cost of a few q-tips.—MEGHANN MARCO
Cleaning Your Laptop Cooling System [Instructables]
Extend Your Laptop’s Life. Clean the Dust Out of Its Heat Sink [Instructables]