Editor’s note: The following review is part of Macworld’s Summer of Mac Gems series. Each business day until the middle of August 2008, the Macworld staff will use the Mac Gems blog to briefly cover a favorite free or low-cost program. Visit the Mac Gems homepage for a list of past Mac Gems.

Curious what’s going on with your system’s CPU, disk drives, network activity, or memory usage? While there are many apps that can track these things for you, my personal favorite is Raging Menace's MenuMeters.

Through highly-customizable constantly-updating menu bar icons, you can view indicators for any or all of those four categories of activity. For each indicator, you can specify how often it’s updated, what type of icon is used, the colors used, and certain settings unique to that indicator.

When you click on an indicator in the menu bar, a menu appears showing even more information. Click the CPU icon, for instance, and see not only the CPU usage, but also your system’s uptime, the average system load, and two menu items you can use to launch Console or Activity Monitor.

If you’re an information freak, MenuMeters presents tons of detail in a well-designed and minimally-intrusive interface.