coconutBattery lets you see how much of a charge your battery currently has, how much it can still hold and how this compares to when it was manufactured. It’ll also show you how many times you battery has been charged.
SlimBatteryMonitor is a replacement for the Apple battery indicator in the menu bar with something more compact.
CoreDuoTemp shows the temperature of your CPU along with it’s current operating frequency. Available in both Widget and Desktop application formats.
Not content with just reporting information Fan Control hands over the base RPM speed and the upper and lower temperature thresholds so you can tweak it to your working conditions.
smcFanControl is alternative fan control program that provides user-defined cooling speeds and an in-menu temperature readout.
MiniBatteryStatus shows you battery status in a compact form on your Dashboard.
The iStat nano widget has added a battery section to it’s list of information.
Temperature Monitor provides comprehensive temperature monitoring including drives and support for non-portable systems, graphs and remote monitoring.