Google, Yahoo and most of the other big boys use multiple favicons for different sections of their services. This functionality has now been delivered to Joomla!
The interesting thing about favicons, is that when you drag a favorite from Internet Explorer onto your desktop, Windows creates the icon from the favicon file associated with the bookmark. When your only favicon image is a 16x16, the resulting desktop shortcut is U-G-L-Y!
Using this component, you can assign different color depths and sizes so the resulting shortcut icon will be appropriately sized and use the correct color depth so it looks as good on the desktop as it does in the browser address bar.
Create your favicons by importing other favicon files, and whatever image formats your PHP installation supports (PNG, GIF, JPG, and sometimes BMP or XCF! It depends on your server.) This extension does preserve transparency in image types that support it, but does not resize, resample, scale or crop images, so you must import images in the appropriate size and color depth.
This component/plugin package can be used in one of two ways.
Using only the component, you can author your favicon and publish it to your template. When published to the template, your existing favicon can be backed up and edited with the component.
Using the component and plugin combination, you can author many favicons and assign them to individual menu items. The plugin allows child items to inherit the favicon of their parent menu items, all the way to the menu root. If a favicon assignment isn't found in the parent items, the configured default icon is used.
When you're happy with your Favicon (menu or template assignments), you can disable the component to un-clutter your admin backend menus. All menu assignments are stored in the plugin configuration, so the plugin runs lightning fast!
This extension makes use of the floIcon class by Joshua Hatfield - http://www.flobi.com