Upuaza Touryou, a user of the NicoNico video hosting site, ordered an electric motor and a remote controller from Amazon.com, then built a tank from those parts and the boxes that they came in! Check out the impressive video at Kotaku.
The model is designed to resemble the Type 97 Chi-Ha, a medium tank operated by the Imperial Japanese Army during the Second Sino-Japanese War and World War II. Upuaza Touryou's replica of it took 2 months of work but a mere $14.50 in parts.