You need to subscribe to some podcasts to expand your working knowledge of stuff. I recommend starting with any/all of the podcasts from Grammar Girl's site, QD Now, www.quickanddirtytips.com. Subscribe from this site or search for the podcasts in iTunes.
The UC Berkeley course Physics for Future Presidents is outstanding. Every semester the course is made available via iTunes. Finding this and figuring out how to put it on your iPhone will be a learning experience well worth the effort.
Books on Tape/CD/MP3 are a natural for the iPhone. Here are a couple of sources to get you started.
- CrimeWAV–short stories read by the authors; detective and crime fiction (adult content).
- Jack Wakes Up–contemporary hard-boiled fiction set in San Francisco by Seth Harwood.
- Scott Sigler–several books all read by Scott. Start with Ancestor for SciFi Horror or The Rookie for sports/action/SciFi.
- PodioBooks–this is where I discovered Seth Harwood and Scott Sigler. Download and listen to the book then donate because you like the book and want to support the author.
- Decoder Ring Theater–radio-style half hour shows. I love the Black Jack Justice series.
- Audible.com–buy normal books for download listening. The first book is free, promotional code GRAMMAR.
- Your Local Library–physically check out the books on CD and use iTunes to add them to your library. Make a "music" playlist of the imported tracks and sync the playlist to your iPhone.