I am in the process of completing a web based application that I will be marketing soon. One of the last features to be added is an iPhone interface. The ubiquity of the mobile platform - most outstandingly, the iPhone - has necessitated this.
There are 2 main ways in which to build any application: hand code everything or use a framework. A framework's job is to take the mundane tasks that need to be done for EVERY application you write and make them simple. Some frameworks also help with code organization.
Web Presence