I just had to have my screen replaced (by a third party repair shop), and while they were at it, they vacuumed out a lot of cat hair for free. Now it runs much cooler, and seems like a new machine!

You can also replace the thermal paste, although now that it's not overheating all the time, I won't have that done until next time it overheats and slows down and I need to have it vacuumed out again.

http://www.mackungfu.org/TheonethingtodotomakeyourMacBookPro...