Are there any resources or guidance out there on how to make iPhone friendly web applications?
In my case specifically, I'd like to use ASP.NET MVC, but since that all runs on the server, I know it'll boil down to just markup/css/javascript considerations.
edit: as I find other resources not mentioned here, I will update the question text :-)
There’s an iPhone article on Sitepoint (which usefully shows you how to target stylesheets at just the iPhone, whilst hiding them from Internet Explorer—Apple's documentation doesn't).
Craig Hockenberry wrote Put Your Content In My Pocket at A List Apart.
A Flickr developer posted some lessons learned: http://code.flickr.com/blog/2008/10/27/lessons-learned-while-building-an-iphone-site/
+1 for Apple’s documentation as mentioned by Boot To The Head—horses’ mouth and all that: they have pretty comprehensive stuff on neat CSS properties that are only really supported by Safari, like CSS animations and CSS Transitions.