Problem solved -- Readable websites on an iPhone
Sunday, July 01, 2007 by Dave Winer.
Scott Mace sent some advice that worked, that made it so that my example page looks good in Safari on an iPhone without the user having to adjust the resolution.
Open this page on the iPhone, you'll see it reads quite well.
If you don't have an iPhone, here's a screen shot.
The trick is to add a <meta> element to the page:
<meta name="viewport" content="width=320">
View source on nytimesriver to see how it works.
Here's a thread where this is discussed.
PS: The same page looks good on a Blackberry too.