Every bartender worth a damn has a cure for hiccups. A wise bar patron should, too.
Learn this and love it. I'll stake my reputation on the fact that this cure, when done properly, works every time. It's not instantaneous, but after 5 minutes, you'll suddenly wonder "Hey, what happened to my hiccups?" This is great bar knowledge and will come in handy for you, your friends, or whenever you want to play Prince Charming to a damsel in... hiccups.
Splash a few squirts of Angostura Bitters onto a lemon slice. Empty a packet or two of sugar in your mouth, drink as much of a glass of water as you can, and then bite into the bitters-soaked lemon. That's it.
There's always some wiseass in the crowd who swears you've got to try his method. Don't trust him. Trust the wiseass behind the bar. I've been using this method for 10 years and it's worked every time.
Sure I could get into all the fancy scientific, chemical, and physiological reasons as to why this works, but I'd just be making it all up.