After the desktop background, icons are the first things that most of us want to change. The traditional method is a two-step process: Select an icon file, press Command-I (or File > Get Info), click the icon in the upper-left, and press Command-C (or File > Copy). Then select the item (volume, app, folder, or file) whose icon you want to change, press Command-I, select its icon in the upper-left, and then press Command-V (or File > Paste).
Panic's CandyBar ($12.95) trumps this method with an approachable drag-and-drop interface that also lets you modify system icons like the Finder and the Trash, which are normally impervious to such changes. To use CandyBar, launch it and drag the new icon file onto the placeholder for a given file, folder, app, or volume. Alternatively, icon sets saved in CandyBar's iContainer format can be installed across the entire system with a double-click. If you tire of your new icons, click Restore All to return to Mac OS X's original set. When modifying system icons, you may have to log out and log back in to see your changes.
