I thought this was a neat article, although I don't own an iPhone, but I am a musician. This new iShred application actually can help familiarize a person with musical chord structures of popular songs. You can learn songs & create your own songs. Although it does not provide a full representation of the whole guitar neck, it does show you what frets are to be played though. I see this app as a fun tool, but also as a learning tool for someone who may be interested in learning how to play the guitar.
http://blog.wired.com/gadgets/2009/02/turn-your-iphon.html
