You can put training for Photoshop, Lightroom, and other Adobe apps in your pocket via the new Lynda.com iPhone app. According to the site,
Courses are often divided by chapters, and within chapters, there are individual tutorial movies. These are all listed in order on the course page. Start watching a course by tapping the first tutorial movie title, and the movie will start to play. Once it is over, move on to the next movie.
For links to other Photoshop-training-on-iPhone resources, please see my previous post.