Recently, I've been working on an iPhone web app for my employer (internal, so I can't share). I based the design and architecture around the iUI library by Joel Hewitt, which became an overnight de-facto standard for web apps. However, after a lot of playing with it and turning it inside out, I've found there are a number of problems which have not yet been fixed.
However, I do not believe that this is the solution to iUI's problems. I feel that a complete re-write in a standardised library like jQuery is the solution. Who knows, I may even find time to write it ;-)
So, here's the file: iui.patched.js
HTML5 Mobile Projects