Preventative measures like these aren???t exclusive to DIY dance parties; they???ve also cropped up on the tech market, with the development of anti-date rape prophylactics such as Boston-based DrinkSavvy???s ???drug-detecting cup,??? which changes colour when such drugs as GHB and Rohypnol touch its surface, or the ???personal drink ID,??? a USB-sized device that can detect a variety of substance