Not only that... but once you make your interface, it will also work on the Google Phone, the PALM Pre, and anything else with a browser that supports the HTML5 specification! Technically, HTML5 is still a work-in-progress... but using jQTouch means you can target the two fastest growing smart phones -- the iPhone and the Google Phone -- with one single HTML-like code base. Even better... you no longer have to struggle with the iPhone App Store to get new versions of your product to your customers.
I kind of figured mobile phone development would eventually become just mobile HTML5 platforms... it's nice to see the jQuery folks leading the charge.
UPDATE: most of my above review was based on testing with the iPhone and the iPod Touch. Both were great platforms for jQTouch. However, I have also tested with the latest and greatest Google 'Droid phone... and on the droid jQuery Touch was horribly unusable. I'm not sure why... it could be because the iPhone has some nifty hardware acceleration for the kinds of animation that jQuery Touch wants to do, whereas the 'Droid has some pretty awful lag. The forms are mostly OK, as are the demo apps, but anything with animations is god awful.
Not sure if this is jQuery's fault or the Droid's fault... however if I were Google I'd work very closely with the jQuery folks to make this all happen... because then it would be a heck of a lot easier to make slick looking UIs.