Favicons

Overview

ICO filetypes can include multiple resolutions in a single file. Make sure to utilize this.

• What Is a Favicon, Why Is It Important, and How Do I Add One? has links to a favicon generator.
• RealFaviconGenerator - Favicon generator, duh. Tool for analyzing an existing site to determine how it will perform relative to major platforms.
• HTML Favicon: A How-To Guide
• Adding favicons in a multi-browser multi-platform world - mobiForge. A lot of detailed information about sizes, platforms, and markup needed to deliver all the formats and sizes of favicons.

Creating ICO files with multiple resolutions

Use imagemagick to combine a series of different resolution PNG files into a single ICO file.

This thread contains a lot of useful examples.