While there are a number of things that can make you short, there are not many ways to get tall. Exercise is not one of them. Stretching does not increase height it just loosens up your joints and lengthens your muscles. Height comes from bones, specifically the bones of the spine and legs. It is true that some activities can strengthen your bones, but in general that doesn't make them longer (or you taller).
The primary determinate of height is genetics. If your parents are tall, then you have the potential to be tall. Of course many children grow taller than their parents, but that is the luck of the genes. Many people, however, do not reach their full potential height. The biggest cause of this is poor nutrition - it really does stunt your growth. Exposure to toxins and some diseases can also limit growth. So while it might not make you taller, good nutrition will help you avoid being shorter.
There are a couple of artificial ways to get taller. Young people can take hormones to accellerate thier growth, including height. The hormones have to be given before full maturity, while the person is still growing. Some people with glandular deficiencies use growth hormones. Another procedure that some "little people" (dwarfs) choose is leg lengthening, which can add a couple of inches to height. In this procedure, the leg bones are broken and then set with a small gap between them. When the bones heal they grow to fill the gap. Repeated several times, this can add a couple of inches or more. However, it is a painful process that can take years.
My advice is to do what most people do when they want to be taller: buy some shoes with heels.
