My wife recently bought a nano, and I wanted to write a simple program for it. It appears that Apple has only released an SDK for the iPhone/iPod Touch without the ability to target the nano.
What are the options to create an app targeted at the nano and install it onto hers?
Your best bet would likely be to get her an iPodTouch or an iPhone and work towards developing on those. They will have support, and familiar tools. I don't think there's any supported development options for the Nano (or every will be). Consider also that the iPad will be an easy transition once you're familiar with iPhone development.