(NOTE: most don't work with BlackBerry because they aren't CSS/DOM level 2 only): 

• PhoneGap-Compatible UI Development Frameworks
• iphone-universal  - CSS/HTML framework for iPhone web development. Contains the iPhone-like Chat Balloons just like SMS on the iPhone (GPL) 
• iUI - make iPhone-feeling interfaces 
• iWebKit - Quick and easy iphone-like web framework, great documentation (LGPL).
• Jo - a lightweight JavaScript framework for HTML5 apps, build with PhoneGap in mind 
• JQTouch - JQuery Plugin for Making iPhone-like apps 
• JQuery Mobile - JQuery's Take on Mobile Interfaces.
• Magic Framework - make fast and smooth iPhone-feeling apps with native-feeling widgets, lists, etc. Also provides an easy HTML5 db storage interface. 
• qooxdoo - Universal JavaScript framework for creating apps for a wide range of platforms, from mobile apps on smartphones and tablets to desktop-style RIAs.
• Safire - iZillow JS/CSS framework (MIT License)
• Sencha Touch – HTML5/CSS3/Javascript framework with a variety of native-style widgets, flexible theming via SASS/Compass, data feature like models, stores, and proxies.
• Unify - HTML5 framework to create native-like applications for smartphones, tablets and desktops
• CiUI - CNET iPhone UI  
• PhoneGap-compatible Javascript frameworks  
• Dashcode - Framework from Apple (only for iPhone) 
• NS Basic/App Studio - Full IDE, drag and drop designer including jQuery Mobile, program using Visual BASIC or JavaScript. 
• The Dojo Toolkit - Flexible and extensible JavaScript framework 
• WebApp.Net  
• xUI - slimmed down jQuery work-alike