Scrolling Long Lists
Another big problem with iPhone web apps is presenting very long lists efficiently. Digg has this problem with their stories and comments and they work around it by breaking stories into pages of ten and omitting all but the top five comments. Apple solves this problem nicely in their Mail app by loading 25 messages at a time and putting a link to get more at the end. Clicking it loads those messages and appends them to the end of the list, allowing you to use the joyous flick gesture to scroll the complete list at once. In my view, this is nicer than breaking the list up into separate pages.
iUI makes it easy for you to use this convention in your own web apps. Simply create a link with target="_replace" and iUI will load the URL it and replace the <a> with the contents of the URL. Again, the URL should not point to a complete HTML document, but only the fragment you want to replace the "Get More" link with.
For an example of incrementally loaded lists, look at the Digg demo again. Scroll to the bottom of the stories list and click on the "Get 10 More Stories..." link.