Bono, Rihanna and Katy Perry have brought this technology into the mainstream quite rapidly to my surprise. The idea of illuminating clothing may seem like an entertaining idea, but there are also great safety reasons why this technology is important to 21st century design.
Cyclists who ride at night would benefit greatly making their journey far safer. People who are stranded in an isolated area would be easy to find on rescue missions. Climatic change is also a factor for wearable technology scientists as they continue to perfect their craft. Talk2myshirt has written a more technical post, for those that want to learn about the mechanics please visit Erich's site.