PrimeFaces is an Open Source library for JSF which lets you create a rich set of components and provide non-rendering JSF extensions to ease development on various webapps. Though not intended for iPhone alone, it serves iPohne webapps quiet efficiently.
PrimeFaces basically has 3 components: UI, Optimus, FaceTrace.
The framework is very powerful and Rich in UI. It has built-in 50+ AJAX based functions that serve most of the effects you would typically need to design iPhone apps.
To demonstrate the power, a developer has hosted a webpage dedicated to the webapps iPhone can run, just like it does any Native application and the corresponding source code is available on Google code.
Checkout the Video for iPhone sample apps: