E.T. and Reese's Pieces refer to a famous example of product placement in the 1982 film 'E.T. the Extra-Terrestrial,' where the alien character E.T. is drawn to the candy brand Reese's Pieces. This strategic marketing move not only helped boost the popularity of the candy but also demonstrated the power of branded content in film, showing how integrated advertising can enhance storytelling and brand recognition in popular media.