Orac


 * Orgone accumulator — A device invented by Wilhelm Reich to trap and focus orgone energy
 * Respectful Insolence — A blog by a doctor and medical researcher, whose nom de blog is Orac, on medical woo and many other pseudoscience topics. Also one of the contributors to ScienceBlogs.
 * Oxygen Radical Absorbance Capacity, which is what antioxidants have
 * A fictional computer from the science fiction television series Blake's 7, an article on which (or whom, as it is theoretically Turing-test compliant) can be found here.