Arecoline - Nicotine's younger and better travelled brother

• alkaloid stimulant present in the betel nut, the seed of the Betel palm (Areca catechu)
  
• the nut is chewed in numerous Asian countries by hundreds of millions of people as a pick-me-up
• chewing the nuts results in a wonderful red-brown discolouration of the mouth, staining of the teeth, oral lesions, and potentially oral cancers (Google image the rest of these yourself, I'm getting too grossed out)
  
• thought to be responsible for addiction to chewing the nuts (haha nut chewing) due to its nicotine-like effects on the brain
  
• nicotine being the addictive substance in tobacco
• no medical use (haha nut chewing) although it has been shown to improve memory and other mental functions
  

Kalant H, Grant D, and Mitchell J. Principles of Medical Pharmacology 7th ed. Toronto: Saunders Canada, 2006.