Since I received such interesting responses to my post on orgasms, I'd like to probe a little deeper on the subject (so to speak). Since my own journey started, I have become fascinated by the subject of female sexual response. Here's a synopsis of what I have learned from reading, and experimentation. If its helpful to anyone, I'm glad. Most of what I find in the way a research is written about female sexual dysfunction rather than normal response. (My theory about this is that if males would worry less about 'enhancement' and more about 'engagement' the problem might solve itself!) I also learned a lot on this topic when I took training to become a sexual assault nurse. When nonconsensual intercourse takes place, the woman's body fails to 'prepare' for intercourse through the softening, swelling, and lubrication of tissue that occurs naturally when consensual intercourse is about to take place. This accounts for a lot of the injury that can occur during forced intercourse.
There are two primary ways the female experiences orgasm (though I've also seen others reported in the research), vaginally via the Grafenberg Spot (or the G Spot) and clitorally via the clitoris. Stimulation of either can trigger an orgasmic response. The clitoris is located between the labial folds and looks like a small bud. It has lots of nerve endings and is very sensitive and light stimulation with the fingers, tongue, or penis (or a vibrator) can produce an orgasm. Use of a rhythmic motion (circular or slapping) helps. The G-Spot (some scientist still aren't sure it exists!) is located on the anterior wall of the vagina (the vagina is the interior genital tract and anterior means towards the front rather than posterior which is towards the back). Feel along the anterior wall of your vagina with your fingers until you feel a rough patch of tissue (it feels distinctly different than the surrounding tissue) about the size of a quarter. That is your G-Spot and again light, prolonged stimulation can produce an orgasm. The G-Spot can be stimulated with the fingers, the penis, or other objects for that purpose. Along with an orgasm, some women experience ejaculation. Female ejaculation (no its not urine) can occur with orgasm. The amount of fluid ejaculated varies from a trickle to multiple gushes (amazingly scientists still debate the reality of this phenomenon). These trickles or gushes accompany the strong rhythmic muscle pulsations that characterize the orgasm.
Notice how little of this has to do with the penis. Most women don't experience orgasm through penile stimulation, but rather by digital (or other) stimulation. Women can and may experience multiple orgasms prior to the male ending intercourse with his own orgasm. Curvature of the penis may account more for enhanced stimulation than length or width (my own theory).
So there you have it, LaborPayne's orgasm primer. The research to verify its veracity is up to you...