Is there something similar for iPhone? Not exactly, but we can achieve the same end:

<!--[if !IE]><!-->
	<link media="only screen and (max-device-width: 480px)" href="iphone.css" type="text/css" rel="stylesheet" />
<!--<![endif]-->

Some versions of IE will apply stylesheets regardless of the media attribute, so the conditional comments are here merely to tell IE not to use this code.

As for the value of the media attribute: not all browsers understand the "only" keyword; they will simply ignore this line. Of those that do understand it, the only one width a max-device-width of 480px is the iPhone.

(So I'm told. I'm taking all of this on faith. But it seems to work.)