I'm a strong believer in jQuery Mobile. It takes an incredible simple, practical direction that I think will be incredibly powerful for developers. If you haven't taken the time to look at the framework, now is a perfect time to check it out.
It is here! Finally. 100% done. (Although Amazon still says it isn't released - that should be corrected soon.) The jQuery Mobile book I wrote with Andy Matthews is now published. The book covers creating jQuery Mobile apps and is up to date to the most recent release. The code is available via Github for easy forking/modifying as you learn. You can purchase via the Amazon link to the left (as I said, it is published so it should ship and I get a small kickback from the affiliate link) or via the Packt site.