I just felt like sharing a tip with you guys. I noticed my 2009 MacBook Pro had unusually bad performances recently. At a point where it was frustrating and barely usable, whereas it had no problem doing the same tasks in the two past years. I made sure my disk wasn't full, that programs weren't running in the background without me knowing, I used iStats Menu to monitor my RAM and CPU usage. Everything seemed normal. The problem? We're in the middle of summer and my room is very hot. Once the CPU reaches a certain temperature, it will automatically underclock itself so that it doesn't overheat. It was common for my computer to reach temperatures in the 80s-90s Celsius during intensive tasks. I decided to open the bottom of my MBP and clean the fan and heatsink. All you need is a small Philips screwdriver and a can of air duster. I felt like it was easy and safe and it doesn't void your warranty. It seemed like there wasn't that much dust stuck in there but it still made a massive difference once I removed it. I dropped about 10 degrees and my whole computer is incredibly snappier all of the sudden, even when I'm just doing basic thing like using Finder and a browser. I feel like I just upgraded my computer, yet it didn't cost me anything, and it's actually good for the longevity of my computer. I would recommend anybody with a laptop that is 1+ year old to do the same, the results are great!