Apple Walkpod
No idea if this is a concept or a modified cassette player, but it definitely dwells upon the idea of an iPod design that was unveiled back in the Walkman's heydays, where cassettes were all the rage then. Of course, you had better amass a healthy collection of AA batteries (or simply get rechargeable ones) if you want to run this since the backlight ought to sip a considerable amount of juice in addition to the playback mechanism. Perhaps a dimmer switch for the LCD display would be a prudent idea?