A must-have for a reference / iPod geek? Merriam-Webster Reference for the iPod . For $9.95, you can get Merriam-Webster‘s 2006 Pocket Dictionary on your iPod.
iPrepPress offers other reference / study guides for the iPod, including several Shakespeare plays, SAT study guides, and Spanish vocab charts. They also offer a few historic U.S. documents for your ‘Pod, including the Declaration of Independence, the U.S. Constitution, and the Bill of Rights.
I haven’t used any of this, but … it’s a great idea. What are the implications for libraries??