By your logic you should only use your walkman when you are walking, or only use your laptop on your lap? [/quote:5d89fb120e]
Ah no. A walkman uses a cassette.
A mp3 player or other advanced listening device uses an audio file.
podcase comes from ipod, defining a universal name for an audio file based on a single player device.
A walkman’s name came from a suggested way of using it, not based on the name on the user product thats used by it.