Okay, time for the pharmacy student to step in here:
Spironolactone does NOT cause you to gain any increases in height.
It was used in a study in conjunction with another steroid inhibitor on boys who had a condition best described as that from an age of 1-3 years old, they had so much testosterone their growth was entirely stunted.
To that effect, blocking testosterone in these boys who now aged around 10 years old, 5.7mg/kg bodyweight, it's no surprise that this normalized their growth.
That is the only known incident of spironolactone causing an increase in height. Whatever you've heard off those non-educated parrots on those TG YAHOO and MSN groups have said some things that are simply outrageous, such as too much estrogen being converted to testosterone, a chemically impossible feat, or many others and them all thinking they're the perfect doctor for you with their cashier job 9-5, it's aggravating.
Spironolactone does not cause an increase in height unless an effect of too much testosterone directly stunts it.
Furthermore Aldactone is not a strong chemical. I mean, the therapeutic effective dose in transsexuals ranges from 200mg to 800mg, that's a LOT.
Compared to a drug such as Sulnar or Altace, or even better for you guys Ethinylestradiol or many others where therapeutic theshold is measured in micrograms, spironolactone is nothing.