The Currency Converter uses flags for its diplayed results. This page is a collection of some of the best free flag images you can use for your website. Some of the the flag images' creator requires you to place a link of their site to your site before you could use them.
The flag images comes in different formats. Some are bunddled as icons, png, gif, or jpg. Some these flag images are even packaged in different sizes. Best of all, they're free!