> What is in danger in the case of an EMP blast?

Any good electrical conductor that is very long or very thin. The EMP induces a current which will heat up the conductor. The longer the conductor, the more current. The thinner it is, the less current is needed to melt it. So powerlines which span the country are vulnerable because they are so long. The wires inside integrated circuits are vulnerable because they are so thin. IPods, computers and cars are at risk because they contain circuitry. They are vulnerable even if they are plugged in because the EMP induces the current in them directly.

The good news is that to protect against EMP you just need a Faraday cage, which is just a good conductor (eg metal) box that completely encloses the item you want to protect.. A tin biscuit box (with lid) could do. It doesn't need to be air-tight as long as the holes are small. It doesn't need to be earthed. The device you are protecting should sit inside it without touching the sides.

I suspect the most practical way to be sure you have an iPod is to get 2, and keep one as backup in the metal box. That's what I do with flashlights. Or you could learn to play the flute?

The above is my current understanding. I suspect we won't really know until an EMP actually hits, what will work afterwards. Keeping electronic gear in a tin box when you are not using it seems like a reasonable precaution.