Dan Grigsby, the founder of Mobile Orchard, just wrote to let me know that he has started offering two-day iPhone programming workshops targeted at developers coming from other platforms like Java and .Net. The workshops are intensive and very hands-on. Over the course of the workshop, Dan walks you through developing seven complete applications and covers many of the core iPhone technologies, including several that are new with the 3.0 SDK such as Core Data.
There are upcoming workshops in the San Francisco Bay Area and in the Seattle area, with more to come in the future.
Dan has been nice enough to offer a $200 discount on the workshop to my readers. You can get this discount by entering the discount code "jeff". Dan has also authored a great series of tutorials that you might want to check out.