An article in the American Journal of Obstetrics and Gynecology in 2001 called the G-spot a sort of gynecologic UFO. Well, the authors of that article may want to start readying themselves for space travel. That is, after they read this paper from Cairo University: "The Electrovaginogram: Study of the Vaginal Electric Activity and Its Role in the Sexual Act and Disorders." In this paper, the authors investigated the hypothesis that the vagina generates electric waves, which affect vaginal contraction during penile thrusting. They found electric waves could be recorded from the vagina. They also postulated that there was a vaginal pacemaker that seems to represent the G-spot, which is claimed to be a small area of erotic sensitivity in the vagina.
So what is this vaginal Loch Ness Monster?
The G-spot is simply a small area located on the upper wall of the vagina, toward the belly, about 2-3 inches from the vaginal opening. The G-spot was named in honor of Ernst Grafenberg, a German physician who, in the 1950s, wrote an article that mentioned an erotic zone on the anterior wall of the vagina that would swell during sexual stimulation.
There are various opinions on the best way to find the G-spot. Some women say that being on top during intercourse works best. Others swear by rear-entry as the best way to hit the G-spot. Some even say that because of its location, a shorter, smaller penis may actually be more effective at reaching the G-spot. A clue to its location may be that some women feel a sudden urge to urinate when their G-spot is touched — not surprising since the G-spot is located right near the urethra.