I have not had a single case of hiccups for over ten years straight now, because of a technique I learned to stop them. I figured some of you might find it works for you as well. As soon as I notice a single hiccup, I immediately breathe in as much air as I can, and hold my breath for as long as possible. This works for me 100% of the time! But if I don't do this on the first hiccup, and allow 2 or 3, I notice it is less effective, so I am sure to take action at the first sign 
Hiccups are strange, aren't they? For a very long time, science could not explain why they happen. I did however find this on Wikipedia:
Phylogenetic hypothesis
Christian Straus and co-workers at the Respiratory Research Group, University of Calgary, Canada, propose that the hiccup is an evolutionary remnant of earlier amphibian respiration; amphibians such as frogs gulp air and water via a rather simple motor reflex akin to mammalian hiccuping.[1] In support of this idea, they observe that the motor pathways that enable hiccuping form early during fetal development, before the motor pathways that enable normal lung ventilation to form; thus according to recapitulation theory the hiccup is evolutionarily antecedent to modern lung respiration. Additionally, they point out that hiccups and amphibian gulping are inhibited by elevated CO2 and can be completely stopped by the drug Baclofen (a GABAB receptor agonist), illustrating a shared physiology and evolutionary heritage. These proposals would explain why premature infants spend 2.5% of their time hiccuping, indeed they are gulping just like amphibians, as their lungs are not yet fully formed.[2]
Hiccups are strange, aren't they? For a very long time, science could not explain why they happen. I did however find this on Wikipedia:
Phylogenetic hypothesis
Christian Straus and co-workers at the Respiratory Research Group, University of Calgary, Canada, propose that the hiccup is an evolutionary remnant of earlier amphibian respiration; amphibians such as frogs gulp air and water via a rather simple motor reflex akin to mammalian hiccuping.[1] In support of this idea, they observe that the motor pathways that enable hiccuping form early during fetal development, before the motor pathways that enable normal lung ventilation to form; thus according to recapitulation theory the hiccup is evolutionarily antecedent to modern lung respiration. Additionally, they point out that hiccups and amphibian gulping are inhibited by elevated CO2 and can be completely stopped by the drug Baclofen (a GABAB receptor agonist), illustrating a shared physiology and evolutionary heritage. These proposals would explain why premature infants spend 2.5% of their time hiccuping, indeed they are gulping just like amphibians, as their lungs are not yet fully formed.[2]
