Folder iChanger provides multiple tools for changing the icon images associated with many different files on your computer. Use one of the many included images, or import one of your own, and then just choose the files you want to assign the new icon image to, and you're ready to go. This tool can help with your organization, or just make using your desktop a little more fun.
The interface of this app is clear and streamlined, although there is no Help file available to explain the features. There aren't too many to check out, though, so it's not too hard to figure out how to use the program on your own. The toolbar across the top of the window contains action tools, and that's where you'll go to select the location to import your new icon image from. Options include icons in the app, an icon file, and executable file, and systems icons. The app comes preloaded with 60 icon images that you can use or save to your computer, either as ICO files or image files. File type options for saving as an image include PNG, JPG, and BMP. To find the files that you want to change the icons for, you'll have to click the "Add Directories" tab, and find them on your computer. Once you have a directory loaded, you can select all files, deselect all files, or go through and pick out files, manually, that you want to assign a new icon to.
This app works well, but it can be a bit confusing for anyone not familiar with this type of program. However, it's free and straightforward to use once you get the hang of it, so it's worth a try if you're interested in customizing the icons on your desktop.