Anyone heard of Dr Michael Colgan, sports nutrition expert? In his book "Optimum Sports Nutrition", he quotes a handfull of studdies that show that large (very large) doses of Arginine have great effects in releasing hGH, however these studdies used Arginine INJECTED. There seems to be less evidence to suggest that oraly ingested Arginine supplements are very effective.
If they are to be effective, they must be consumed on an empty stomach, and prefferably an hour before a workout, and (definately) just before going to bed. In his book, he states, that at his training institute, athletes are instructed to wake up during the middle of the night to take further multi gram doses of arginine, as it has something to do with the fact that hGH is at its highest approximately an hour after falling asleep, which, is another reason why sleep is so important.
Also, (supposedly), Arginine should not be taken with other Amino Acids or any protein at all, expect Ornithine, as the other AA compete with arginine.