Radio

The Radio is a reoccuring item in the Don't Starve universe, proven to exisist in some capacity both in the world Wilson is abducted from, and the wilderness created by Maxwell.

Appearances
It first appears when Maxwell makes first contact with Wilson in the Forbidden Knowledge video, and is used as both a means of verbal communication and a way to channel information into Wilson's brain.

The radio makes a second appearance in the wilderness, as it makes up the primary component of the Divining Rod. This time, it broadcasts a sound (as well as a visual cue) that increases in intensity the closer the player approaches to a Thing, Wooden Thing , or Maxwell's Door. As a part of the Divining Rod, it is required to activate the Wooden Thing in order to move from world to world, and ultimately acts as the key to Maxwell's release from the Nightmare Throne.

Background
As stated by the developers,

"The  radio  is a Voxola PR-76, manufactured in 1919 by the Voxola  Radio  company of Sidney, Ohio. The  radio  offered revolutionary sound and reception quality for the time, and was promoted by an intense national marketing campaign. Very few units were actually produced, because the factory was destroyed in a fire only days after production began. Voxola founder Robert Wagstaff went missing the night of the fire, and the company declared bankruptcy soon thereafter. "

Speculation

 * It is possible that Wagstaff made a deal similar to Wilson's for "Forbidden Knowlege" in order to produce the advanced radio. The marketing campaign may have also been influenced by Maxwell through Wagstaff in order to distribute the radios as widely as possible. Since the radio is demonstrated as Maxwell's primary means of interaction with Wilson, it can be infered that his plan was to distribute the radios as widely as possible to provide him with a greater pool of potential "playthings". Since the fire shut down mass production, it is highly likely that each of the characters appearing in Don't Starve received a radio from that limited run.
 * It can be infered that the creator of the radio, Robert Wagstaff, was abducted by Maxwell on the night of the fire. All Don't Starve characters, short of Maxwell himself (and this may be debated due to the previous existance of William) posess a first or last name beginning with W.