Foxhole Radio - Quick, Simple and Powerful Project Fun

I stumbled on this wikiHow article that describes making a Foxhole radio, and I was instantly impressed. And what's foxhole readio? It's a style of crystal radio that was constructed from spare parts during WW II. Construction as you can imagine is dead simple, yet it's functional -- how cool is that? Even I can appreciate how simple this schematic is:

Here's a YouTube video that walks you through the entire process. With the exception of the use of the blow torch, it looks pretty kid friendly too. This one's going on the fun project todo list.