I posted a while ago about blowing out my laptop with compressed air due to some overheating issues and whatnot.
Anyways, just thought I'd report back that since I've done it, my computers fan doesn't even turn on, that's how "cool" it runs now.
It used to shut off after a half hour or so and the bottom was hot enough that you literally could not touch the plastic.
I highly recommend that if you have a laptop older then 6 months or so and an air compressor that you do this. I'm amazed at the results, myself.
I didn't go crazy with the air (about 80 psi and a foot away), but it sure made a difference!