Overclockers Online has put up a review up of Macpower's Digidoc 5 unit which allows people to measure a truckload of temps, monitor voltages and control fans.
The main device has a large LCD screen with an orange backlight (very c00l indeed!), 5 buttons on the front and a 40mm fan. The Digidoc can measure op to 8 temperatures inside your case by using external thermal sensors. On each temperature channel, you can also attach a fan to control the temperature. Because the Digidoc5 supports up to 8 channels, you can attach up to 8 fans (60mm - 120mm high performance fans) and thermal sensors! Now that are a lot of temperature readings when attach all of the sensors I'd like to note that MacPower includes two types of thermal sensors in the Digidoc5 package, two flat sensors and six bulb sensors.Read more