As far as I know, human growth is an hormonal regulated process. So taking some hormons would allow one to grow "forever". Actualy, Robert Wadlow the tallest man in guiness records was a man who continued growth in adulthood were due to hyperplasia of his pituitary gland, which results in an abnormally high level of human growth hormone.
Also, [stretching may lead to damages][1][2]
stretching may lead to damages, be careful that here too you should respect your body and its limits.
[1] http://www.livestrong.com/article/431962-does-stretching-cause-damage/ [2] http://www.endalldisease.com/the-myth-of-stretching-for-flexibility-and-the-damage-it-causes/