I\'m not sure what the correct size should be.
Many sites seem to repeat that the apple-touch-icon should be 57x57 pixels but cite a broken link as their source.
From the Google cache of Apple Developer Connection - Web Apps Dev Center - Designing Content...
Create a Web Clip Bookmark Icon
iPhone and iPod touch allow a user to save a Web Clip bookmark to your site on their Home Screen.
To specify a bookmark icon for all pages of a web site, place a PNG image named "apple-touch-icon.png" at the root directory of your web server - similar to the "favicon.ico" for site icons.
To override the site bookmark icon on a specific web page, insert a element similar to within the
element of the page.The bookmark icon dimensions should be 57x57 pixels. If the icon is a different size it will be scaled and cropped to fit.
Safari will automatically composite the icon with the standard "glassy" overlay so it looks like a built-in iPhone or iPod application.