Everyone knows (or should know) what a favicon is, you've probably got one on your website and if you haven't, you should. They're great for finding a particular site amongst a long list of bookmarks and I for one have a lot of bookmarks.
Recently though you've been able to add websites to your iPhone/iPod Touch's home screen by hitting the '+' while in Safari, then pressing 'Add to home screen'. This then adds an icon to your long list of app's but just performs as a shortcut to the desired website.
First you need your icon, design it to 58 by 58 pixels and then save it as PNG. Remember, you don't need any of the fancy rounded corners or glow effect on your icon, the iPhone/iPod Touch will handle that for you.
Now for the code, add this into the
<head> of your site and give it a whirl.
Here's what my site looks like when you try to add it to your home screen.