Someone e-mailed this today to a list I’m on. It is a bit simplified, but this chart is meant to introduce people to the concept of electromagnetic radiation. Click on it to get a slightly larger version of the chart.
UPDATE 12/8/12:
Here’s another from Fred, W8ZLK:
Dave, N8SBE says
I guess it would be OK, if it wasn’t riddled with technical inaccuracies. Ham radio, for instance, is not limited to less than 3 MHz, nor is it primarily there. There are plenty of others, but that one jumped out at me, of course.