This is one of my essential apps.

LoadInDock is by far the best CPU monitor that I've ever used. I love being able to tell exactly how much processor time is being used at any given moment. I keep it in my dock right next to the Dashboard icon (or the Finder icon if I'm using Jaguar/Panther), and I have it set up to automatically launch at login via the Accounts pane in the System Preferences.

On many occasions, LoadInDock has helped me realize that an application has hung, locking up the CPU at 100% load (after which I can use Terminal to check which process is hanging using the "top" command and end it using the "kill" command, which often works better than trying to Force Quit). If for no other reason, I recommend LoadInDock to help advanced users keep a more watchful eye on their system.

The main reasons I like LoadInDock better than Apple's Activity Monitor:

1) Customizability: LoadInDock has more configuration options than AM
2) More Visually Appealing: LoadInDock looks *much* better than AM
3) Percentages In Dock: AM doesn't give you the option to show in numerical form the total CPU percentage (or kernel, user, or nice percentages) in the dock
4) Longer CPU History: History stays longer in LoadInDock's icon than in AM's
5) Less CPU Load: LoadInDock uses much less of the CPU than AM does, according to the command-line utility 'top' (even when the main AM window is closed)

I've used it a long time ago, before Panther and the new Activity Monitor. Now, it even uses more memory than AM. But it's nice to see this nifty utility is still alive. Thanks. :)