How do I put a custom icon next to the URL in the address bar and bookmark list?
This functionality is available in Microsoft browser Internet Explorer version 5 and above, KDE's Konqueror and the recent Mozilla builds. On IE5+ the favicon only takes effect only after the page is bookmarked.
Since the icon can be displayed in different sizes in various locations (desktop favourites bar, IE favourites lists, etc.), a multi-resolution .ico works best which contains a 16x16 icon, plus a 32x32 icon in both 16-colour and 256-colour resolutions.
Rather than using a simple "favicon.ico" file, you can use:
<link rel="shortcut icon"
This allows you to have icons for individual pages, and seems more likely to eventually be supported by other browsers.