It's a rare movie-goer indeed who hasn't occasionally wished for a different ending to a film, but a new technology platform aims to make such sentiments a thing of the past. With a specialized headset and software, UK-based MyndPlay now lets users determine movies' outcomes themselves using just the power of their thoughts. Billed as “the world's first mind-controlled media player and platform,” MyndPlay uses a specially designed EEG headset from partner NeuroSky to measure the wearer's brainwave signals and monitor his or her attention and relaxation levels. A free software download for Mac or Windows, meanwhile, receives that data…