I've been doing a bit of experimentation with web pages in the iPhone, and I've realised the first major problem is trying to prevent the iPhone from zooming way out on a web page, making it rather difficult to work with and more difficult to read.
One would assume that a 100%-width layout would be good enough for the iPhone's Safari to stop setting the browser width to 964px. But alas, it's not.
<meta> tag in the
<meta name="viewport" content="width=320; initial-scale=1.0; maximum-scale=1.0; user-scalable=0;"/>
It turns out this was all well documented on Apple's site, iPhone for Web Developers. There are lots of other techniques discussed like how to specify stylesheets and integrate with the built-in Google Maps application.
I hope that other device manufacturers implement things like the
<meta name="viewport"> tag and the only-for-certain-widths stylesheets. The iPhone may not end up in everyone's pocket, but we will need to make web sites and applications that work across an ever-wider range of devices.