Apple 
iPhone Startup Image and Home Screen Icon
The main HTML page contains several elements to influence the behavior of the web page on an iPhone. The following two dictate the images that will be displayed on the iPhone's home screen, and during application startup, when a link to the web page is added to the iPhone home screen:
<link rel="apple-touch-icon" href="mobileviewericon.png"/>
<link rel="apple-touch-startup-image" href="mobileviewerstartup.png">
Both of these images are located in the root MobileViewer folder. You can use your own images instead by modifying the links in the HTML page. Documentation for the required size and format of these images is located in the Apple Safari Web Content Guide ( http://developer.apple.com/safari/library/documentation/appleapplications/reference/safariwebcontent) in the section: 'Configuring Web Applications'.