For the iPhone web application I have been working on, I chose to use iUI which has worked out quite well. Now that I’ve got to a reasonable point in functionality I have decided to take a look at JQTouch which is an extension/addon that builds on top of JQuery.
First thing I’ve noticed is that sliding in a new page div also slides in a new page header. In fact it looks like you have to tell it about any page header and buttons you want each time you send a new ‘page’. Not sure if that’s fixed or not. I can see it gives you more flexibility regarding page layout and behavior, but also means there are more things to consider when laying out the page structure when compared to iUI.
Still, it’s early steps yet, lots of learning ahead (sigh!).