The world of iPhone application development is evolving rapidly, and developers have a growing list of development tools from which to choose. I've created a list (incomplete I'm sure) of some of the more popular tools and frameworks.
MobiOne, an IDE that utilizes the power of WebKit browser engine, is an enterprise-class emulator that enables development of mobile applications using web standards such as HTML 5, CSS 3 and JavaScript.
iWebKit, the "Simple and Advanced" framework for building iPhone optimized websites, now has themes.
For anyone who wishes to create an iPhoneized website but does not want to start from scratch, using a framework is definitely the way to go. iWebKit is one of those frameworks, touting itself as the "simple but advanced" webkit.