smcFanControl

Manage the fan speed and activity when working on a Mac. Check the current temperature readings and increase or decrease the rotations speed of the built-in hardware fans, monitor the changes in conditions such as loading and cool runnings. Save configuration profiles.

smcFanControl... Control the fans of every Intel Mac to make it run cooler.
smcFanControl lets the user set the minimum speed of the build in fans. So you can increase your minimum fan speed to make your Intel Mac run cooler. However in order not to damage your machines smcFanControl doesn't let you set a minimum speed to a value below Apple's defaults.smcFanControl is a great system utility for any Mac user. The application lets you see your Mac's CPU temperature and to control the speed of the internal fans to cool your Mac down when needed. It runs on the Menubar. Its icon shows the current temperature and speed of the fan. This app is very simple, but it is incredibly useful. I use a Macbook Pro, and it can get a bit hot when running design software or games. Flash is another app that makes it incredibly hot. I would like my Macbook to last forever, and make sure it never runs too hot is a first step.

From the Settings window, you can change some of the icon options, including what is shown in the Menubar (temperature and fan speed, only temperature, etc). You can also choose if you want to see the temperature in Celsius or Farenheit. But the most important thing you can change in this window are your fan speed presets. By default, there are two presets: Default and Higher RPM. Default makes the fan spin at 2000rpm, while Higher RPM is configured at 4000rpm. My Mac's fans can go up to 6000rpm, and that is what I have set in one of my presets. So, when I notice that my Mac is getting hot, I run the fans at 6000rpm for a few minutes to cool it down.

All in all, this app runs great, and it supports most Macs. It is a great tool to have if your Mac tends to get hot.