Glutamine is scientifically proven (I do not have the sources at hand, believe me at your own risk) to aid the recuperation/recovery of EXTREME athletes, so for example, if you are an olympic or professional athlete, I would recommend glutamine. However, due to its price, and the fact that most non-pros need it, I would advise you to save your money and spend it on a good quality whey protein.
Hope our master Kian can post here too =P