If your curious about how Icons are created.

I have always been curious as to how icon files differ from regular images that we are used to seeing on the web and on our desktops.
I found a great page while looking for an Icon editor/creator. This page explains Icons very well. From task bar icons to shortcut Icons. It gives the size difference for MAC icons as well. They also describe the difference betwwen XP icons and Icons for previous desktop and server OS versions

"An icon is a graphic image, a small picture or object that represents a file, program, web page, or command. Icons help you execute commands, open programs or documents quickly. To execute a command by using an icon, click or double-click on the icon. It is also useful to recognize quickly an object in a browser list. For example, all documents using the same extension have the same icon.
That's almost all you need to know if you only use icons. But to create icons, which is the purpose of Axialis IconWorkshop, you need to more about them. What's the difference between a standard image and an icon image? What's the structure of an icon? How to create an icon which will display correctly on all screen configurations (size, colors...)? Can we save an icon to a file? Can we assemble several icons into one file? What about the new Windows XP icon format? "

Read the rest . . .

I have not tried their software yet but when I do I'll post how well it worked. I read that it integrates somewhat with adobe photoshop.