Scantily clad young women sitting inside brightly-lit glass kiosks with flashing lights and neon signs are a common sight along Taiwan's streets. When cars pull up, the women totter out in high heels and miniskirts to deal with customers through the passenger-side windows. But these ladies are not selling sex, they are peddling betel nuts.

Betel nut is a fruit from the areca palm tree that is found in abundance in many Southeast Asian countries including India. It is chewed wrapped with betel leaves, sometimes with tobacco and slaked lime, but the bright red juice that it produces is spat out. Betel juice stains can be found on walls and footpaths throughout south-east Asia. The nut is taken for its stimulating and psychoactive effects, and is a popular alternative to chewing tobacco. It is the world's fourth-most popular psychoactive substance after nicotine, alcohol and caffeine. Chewing betel nut is said to produce an euphoric and warm feeling. Add the ladies in skimpy outfits, and you get an even headier mix.