I’m not a smoker, and I don’t carry a lighter around in case anyone needs a light.  However, I could totally see myself with a miniature laser lighter.  In fact, if you want to build one, feel free to grab a BIC Lighter, a blue laser diode, two 1.5 cell batteries, two magnets, and check Instructables for details on how to assemble a Cheapy Laser Lighter Burner.