Iconographer is a fully-featured icon editor. It allows you to both change the icons of items and to edit the icon resources used by various programs. Iconographer has been created from the ground up to deal with many icon formats, including: classic Mac OS (8-bit icons only), Mac OS 8.5 (32-bit icons with 8-bit masks), Mac OS X (128 x 128 icons in .icns files), Windows and Windows XP (.ico files), and Mac OS X Server (48 x 48 icons in .tiff files).
Due to its flexibility, Iconographer is useful to both beginners and advanced users. It can be used for a wide range of tasks, ranging from simply creating some customized folder icons to editing complex resource files for an application to converting icons between platforms.
Very nice icon editor for OS X, can create Windows icons too. I just used it to create a nice replacement icon for Ben Shanfelder’s excellent free program Audio Recorder, which hopefully he will like and incorprate into a future release if he wants.