That was asserted as common knowledge in this GD thread, but nobody seems to have a cite.
I went to graduate school in sexual differentiation. The answer to your question is almost certainly yes but it is hard to prove because the rates of homosexuality are notoriously difficult to show within a tight range because of several different kinds of biases.
Many reputable studies that I read converged on a 3 - 5 % incidence for homosexuality in males and 1 - 2% in women. We can sit here and argue the exact numbers all day and not get very far because there is no way to know exactly.
I don’t have a cite handy, but I recall surveys showing that more women identify as bisexual then men. Could that also skew the numbers some?
Bisexuality screws up the numbers a lot. It is difficult to poll people when the definition of bisexual varies greatly amoungst them. The results for several studies have yet to yield consistent results.
As Shagnasty mentioned and the last study I read about 4 percent of men identify as exclusively homosexual and 2 percent of women identify as exclusively homosexual.
Damned Bi folk. Just pick one already and quit messing up the numbers!
(kidding, just kidding!)
1 - 2% in women? Sadly, I have been misinformed by Cinemax. I should compose a strongly written letter to their management.
Boy, I sure hope so. That would mean more straight women for me! 
Just because there are more straight women, doesn’t mean they are for you.
Not if I convert them all to the Dark Side. Mwoooohahahahahha!
Do you eat a lot of toast?
Which leads us to another source of error, that “wife bi-curious” can mean “husband won’t shut up about it.”
Also the issue of things like LUG(s) (Lesbian Until Graduation) hint that women may go through a temporary lesbian phase at some point with no commitment to follow that, and to return to heterosexuality at a future time may skew the numbers. Sort of a communal masturbation phase.
A fair amount, yes. 
From the various Human Sexuality text books I have laying around:
Laumann et al. 1994 - While 5.5% of women reported that they found the idea of having sex with another woman appealing, only 4% had done so since the age of 18 and less than 2% had done so in the past year.
While 9% of men reported that they found the idea of having sex with another man appealing, only 5% had done so since the age of 18 and only 2% had done so in the past year.
Muir 1993 (studies in France, Britian, Norway, Denmark, and Canada) - Homosexuality is found in 1% to 3% of men and a slightly lesser percentage of women.
Janus and Janus 1993 - 9% of men and 5% of women report having homosexual experiences frequently or on an ongoing basis. 5% of men considered themselves bisexual while only 4% considered themselves homosexual. 3% of women considered themselves bisexual while only 2% considered themselves homosexual.
The latest book I had at home was published in 1996 so I will try to find good, recent stats.
However, the problem with self reported studies is that there are many men who sleep with other men many times who don’t consider themselves anything but heterosexual. Some women who consistently sleep with other women do the same.
Another thing just to toss into the ring: women who simply think (for decades sometimes) that they have very little sexual drive (having only had sex with men, and not really enjoyed it but never questioned the situation due to societal expectations about female sexuality) – until they have a sexual encounter with a woman and realize that, yes indeed, they do have a sex drive after all. This sometimes occurs later in life. Up to that point, the women have identified as straight. This might mask numbers of women who are attracted to women, but for whom it never occurred to identify as anything other than straight.
I don’t know of any studies of this phenomenon. But the anecdotal evidence suggests that it ought to be investigated.
While you’re at it, please inform them that being a plumber or a pool boy is not nearly as rewarding as the porn industry would have us believe.
It has, however, been scientifically proven that delivering pizza will get you, in the words of behavioral psychologist Dr. Dong Hang Lo, “more ass than a toilet seat.”
The joke, from the coming out episode of “Ellen,” is not that the recruiter gets a toaster. The joke is that the recruiter gets a toaster oven.
In her defense, I don’t own a toaster but I have a nice toaster oven, given to me for my birthday by a straight friend as a tongue -in -cheek joke (and yes my mind when to the dirty place when I said “tongue-in-cheek”)
I do, in fact, make all of my toast in the toaster oven. I am the Toastmaster. Just like my oven.
For some reason I now have an image of a woman dressed in all leather with spike heels on, brandishing a whip at the toaster oven.