Battery Health Monitor
Battery Health Monitor is a free utility for PowerBook and iBook owners that monitors virtual all battery health parameters and displays them in an easy-to-read format.
coconutBattery isn't just a tool which shows you only the current charge of your battery - it also shows you the current maximum capacity of it in relation to the original capacity your battery had as it left the factory.
(commercial) CoolBook is a tool for the MacBook and MacBook Pro computers. It lets you monitor the frequency, voltage and temperature of the CoreDuo / Core2Duo CPU.
Fan Control is a preference pane that allows to change the fan speed and ramp up temperature to run your MacBook or MacBook Pro cooler.
This application is a GUI for the iCook kernel extension. iCook is a small OS X kernel extension that allows simple overclocking of the IBM 750FX processor, found in some of the iBooks (600...900 MHz).
InsomniaX disables the sleep mode on a Apple Laptop.
Lab Tick is a backlight control for PowerBooks/MacBook Pros.
LCDtest is a utility that simply helps you test your LCD screen for bad or stuck pixels.
MiniBatteryStatus is a small Dashboard widget that monitors battery status, charge percentage and remaining battery life. Integrated with Growl to alert you when it's time to recharge your battery.
MultiAlarm is a security tool that is used to defense against unauthorized users from using a machine locally or stealing the machine. When the alarm is armed, depending on the configuration this application the movement of the laptop or mouse and keyboard will set a sound alarm and perform other alerts.
smcFanControl lets you control the minimum speed of your macbook's fans manually.