don't do it. start exercising everyday 40 to 70 min 6 days a week. do streching, yoga, run, bicycling, swimming and you will see results right away. go to a pro and ask for specific exercises for increase height. You can add up 3-4 inches and if you are persistant even more. Some poeple add up up to 7 inches.

Is there such a thing?

Though I don't you'd gain as many inches as charis suggests, your best bet is good food, good exercise, good sleep -- especially since looking at your profile, you're still in growing-age. Seriously, eat well. Milk. Lean meats. Spinach. Milk, Milk, yogurt, cheese, milk. I swear my brother grew some 4 inches his senior year of high school, the damn cheater, drinking probably half a gallon a day. (we eat crap at my parents' house though, lots of ramen and tuna helper, so if you ate better all around, you'd probably have good results without drowning yourself in milk. ;) 8 hours of sleep minimum. I get 9, it's great, I'm not a zombie in the morning. (Well, I am, but only for ~10min, not an hour) Exercise -- especially low-impact. Running and jumping are high-impact stuff, but swimming, walking, aerobics, weightlifting, yoga, bikes -- low-impact. To actually answer your question though? The one "leg lengthening" method I know involves breaking your leg in multiple places, inserting pins and screws through the skin, and turning the screws every day or so. It's *excruciatingly painful*, for about a milimeter a day. You're on crutches or a wheelchair if you're doing one leg, wheelchair or bedrest if you're doing two. So, to grow an inch, you'd spend a month in agony with useless legs. That doesn't even count physical therapy after the fact. For this reason, it's generally saved for people who are filthy stinking rich and can afford to take 6 months to a year off work just to grow 2-3 inches, and/or children whose legs are way uneven (fix it now before it gets worse). There are variations, but they all involve breaking the bone and then pulling it open as it heals.