Check out this video in which the late Jimmie Driftwood shows off his guitar. According to his Wikipedia entry, "Driftwood learned to play guitar at a young age on his grandfather's homemade instrument. Driftwood used the unique guitar throughout his career and noted that its neck was made from a fence rail, its sides from an old ox yoke, and the head and bottom from the headboard of his grandmother's bed. This homemade instrument produced a pleasant distinctive resonant sound."
Thanks to Karl for bringing this unique guitar to my attention.