August Trometer's new PDF book, Optimizing Your Website for Mobile Safari" just debuted. I am not much of a web designer myself but I may cough up the ten bucks to pick up a copy of this ebook. Topics according to the web page include Mobile Safari detection, Webkit-specific CSS attributes, and how to use iPhone-specific features via web tweaks. iUI, Joe Hewitt's iPhone-specific webpage design kit, doesn't appear in the write-up, and I'm not sure if Trometer covers using it or not.
Full disclosure, I have worked with AW/Pearson and will be doing so again.