I learned yesterday that Safari on the iPhone will load the apple-touch-icon png file from a website if you add a bookmark to the home screen. This can either be a file at the root of the website or the file can be specified with the link tag in html.
To see a typical use, you can go to amazon or twitter, then click the "+" at the bottom of Safari and then select the "Add to Home Screen" button. This brings up a window where you can name the screen. It also shows you the icon it will use.
Sure, one icon is interesting. But then I wondered what I could do with a bunch of icons. Using Photoshop I diced up a photo into sixteen little images and saved each individually as a png file. Then I created sixteen html pages, each with the link tag referring to a different png file. I put all of these on my Mac in the Sites folder. From the iPhone I used Safari to go to each page and add it to my home screen. Once they were all saved I rearranged them on a new screen.
Not that I think anyone would really want this on their iPhone, but the first image is here. There is a 'next' link for the second image, and so on.
To help create the icons in the right place I first created a mask. If any is interested in this leave a comment and I will add it.
Sure it is useless, but who cares.