Simple list of some well known mobile UI frameworks you may want to use on your next mobile web project.
jQuery Mobile
Touch-Optimized Web Framework for Smartphones & Tablets
jQTouch
A jQuery plugin for mobile web development on the iPhone, Android, iPod Touch, and other forward-thinking devices
Sencha Touch
The First HTML5 Mobile Web App Framework
Jo
The simple app framework for HTML5. For iOS, Android, webOS, BlackBerry, Chrome OS & anything else with HTML5
iUI
User Interface Framework for Mobile Web Devices
SproutCore
SproutCore is an open-source framework for building blazingly fast, innovative user experiences on the web