"Made In Japan" is a recurring feature on the Makezine blog. Vol. 9 has a link to homemade tiny tube-based radios. Here's one built into a vending machine bubble.
*Tube portable radio made into gachapon capsule.
*About the same sensitivity with standard 4-tubes portable super het.
And loud speaker is also built in.
*Comprise minimum number of necessary and easy obtainable parts.