Friedman is then reminded of the old Richard Pryor story about two old black men urinating into a river from a bridge above. "Wow, that water's cold," says the first one. "Yeah, and deep, too," says his friend.

Friedman considers this obsession with trophy size a male preoccupation. "The evidence I've looked at -- and I've looked at a lot -- shows that the people who've done most of the obsessing about how big a penis is, and I believe still are, are men." Then he adds, "This isn't to suggest that there aren't women out there who prefer a larger-than-average penis. Some, I'm told, meet prospective dates by subscribing to 'Hung Jury,' a newsletter featuring men with penises that measure at least eight inches in length -- about two and a half inches longer than the typical penis."

As long as we're on this subject, does a monstrous trouser snake give a better orgasm to its owner than the smaller skin flue? "Sensitivity in the penis, and everywhere else in the human body, is typically measured by density of nerves in a given area," Friedman answers.

"A large penis is not necessarily more sensitive than a small penis, nor does it have a larger orgasm." Friedman then clarifies what's really important. "Generally speaking, a penis functions better -- for the man as well as the woman -- if it is thicker than usual, rather than longer than usual. A penis that is really, really long -- like that on Long Dong Silver, for example -- often has difficulty becoming completely hard because it's harder for the blood inside to get completely trapped inside the penis. (It's a simple matter of hydroengineering.) A urologist I know who saw a porn film starring Long Dong Silver swears the poor guy was never fully erect, and that he spent much of the film swinging his penis around as if it were a piece of rope."

As a penile concern, the practice of circumcision is as controversial as dick size. According to Friedman the only compelling reason to be circumcised is tradition. "There's certainly no convincing medical reason for the practice," Friedman says. "Parents want their sons to 'look like' their fathers." Then he adds, "One of the prime reasons why 'hygienic' (nonreligious) circumcision became routine in U.S. hospitals a century ago is that it was thought to reduce the likelihood of masturbation later. This was total bunk, of course, but neonatal circumcision is still the norm in the U.S., though the number of noncircumcised males is growing."

Friedman then warns that much anti-circumcision dialogue is thinly disguised anti-Semitism. He adds, "Also anyone who says there is no difference between removing the male foreskin and the female clitoris is lying or seriously deluded. A circumcised penis retains its sexual and reproductive powers. A woman who has a clitorectomy loses her natural libido and any possibility of erotic pleasure. She is mutilated; a circumcised man is not."

Perhaps the ultimate violence associated with the object alternately called a prog, spear and ramrod is rape. Friedman thoroughly examines the penis's inherent desire to intrude where it is not welcome. But no definitive conclusion is reached. "Anyone who thinks rape is related to testosterone levels in men is completely and demonstrably wrong," he says in an e-mail.

"One of the weakest arguments made by feminism in the 1970s was the attempt to link male-on-female rape to testosterone and/or pornography. That linkage just does not exist, at least not in a provable, scientific sense." His book finally concludes: "What we can say ... without any fear of contradiction, is that testosterone creates the organ that many men refer to as their manhood, the same organ many feminists liken to a battering ram."

Despite Friedman's focus on the penis's tendency toward violence, the thing that surprises him the most is that, after millions of years of hard-ons, scientists only just figured out in the early '80s what makes the beanstalk grow. He describes how Giles Brindley, an English physiologist, gave new meaning to the term "scientific presentation" at the 1983 meeting of the American Urological Association.

"Brindley [was] experimenting with drugs that could give a man an erection on demand. Rumors of his research got him invited to the AUA convention in Las Vegas, where one American challenged him to support his controversial data 'beyond charts, tables and graphs.' Brindley decided to do just that. Just before he took the podium, he went to a nearby men's room and injected himself with his experimental medication. Then, after presenting his data, Brindley stepped in front of the podium, unzipped his fly and presented himself. There it was, for all to see, the, uh, 'evidence.' Never before had so many penis doctors seen another man's erect penis. And in this comical moment, modern medicine, male sexuality and man's relationship with his penis, were changed forever."

Friedman finishes the tale, and one understands why his friends have nicknamed him the "Dick Guy" or just "Dick" or finally, "Nixon." "I can't tell you how many times I'd be at a party," Friedman says. "When someone I knew would drag over someone I didn't, then point to me and say, 'Hey, this is the penis guy!' Trust me, it's a helluva conversation starter. Of course I had to explain that the book wasn't about my penis." Then he adds, "That book, after all, would be too heavy to hold."

Everyone's a comedian.