Yeah, I don\'t exactly get why you\'d need diazpham for this demo although as shingoku indicated, your screen will be less "jiggy" by "using" the drug.
As asking the particular question would lead me to believe, you\'ve apparently not played the PSX MGS game yet (or thru to completion). If you had, then you\'d have found the drug to be most beneficial when you had the long-range sniper rifle. Holding that puppy up and keeping it "still" was nearly impossible regarding squeezing off a successful round at an enemy b/c your (ie Snake\'s) breathing affected the "aim" of the gun up and down with each "breath". Pretty cool!!!