The Sony Watchman was pretty cool.
Here are some controls from the right side. Further up (right) is a volume knob missing from this shot.
Here is the left side, with ports for headphones and even external power. There's also some permanent advice to "see instruction manual", but that thing is long gone.
Here is a very blurry shot of the corroded battery connections. Maybe I was recoiling to quickly in disgust. The Watchman worked on just four AA batteries.