iPhone and the meta viewport tag
If you want your content to look perfect on an iPhone you must use the viewport meta tag. Without it, your page may look like thumbnail. I had not heard of this tag until now. But it does the trick.
<meta name="viewport" content="width=320, user-scalable=yes">
Add this tag to the head section of the HTML page. If you set user-scalable to no, then your users wont be able to zoom in or out, so it is friendly to set it to yes (unless you are writing a page that is not meant to be zoomed in).
