移动手持及平板电脑和网页应用设计UI规范
Official user interface (UI) and user experience (UX) guidelines from the manufacturers, links to which you can find below, are a source of inspiration for mobile web and app design. Here, you will find guidelines, samples, tips, and descriptions of common mistakes. Many of the guidelines focus on native application development, but we can apply most parts of them to mobile web design too.
Remember to provide the best possible experience on each platform. Do not deliver an iPhone experience to a BlackBerry user. Every platform has its own UI and usability guidelines that every user is expecting on your app.
iPad Human Interface Guidelines iPad HIG was merged with iPhone in iOS HIG (see above)
More tips on mobile web design on the Programming the Mobile Web book.
Do you know any other UI Guideline? Insert the link on the comment area.