Late to the party, I thought I'd just throw in the following observations. I have actually participated in speed dating a few times; I found it fascinating and educational.
The speed dating events I attended allowed about 3 minutes per interview (or "date") before proceeding to the next pairing. Each attendee is provided with a notepad, complete with numbers corresponding to the number on a nametag worn by each participant. (Names are also on the nametags, but there are often duplicates so numbers are required to avoid ambiguity). This way you can make notes so that you'll remember something about people you are (maybe) interested in. You are also given a card with a box to check for each number if you would like to see that person again. The notes are for you to take home, the card you submit to the organizers. The notes can be useful when filling out the card, if you want to deliberate a bit on your choices at the end instead of making a snap judgment after each meeting.
One thing I noticed is that, as the man, I did not really have much time to make notes in a non-awkward way. My options were to a) writing down things about the person I had just spoken with before continuing to the next table b) writing down something about the previous date when I arrive at a new table or c) writing in transit between tables. All of these are physically or socially awkward, or both, as well as time-pressured. Meanwhile, the women who remain seated can use the time between one man leaving and another arriving to write notes; even if the next man arrives before she has finished, it is much less awkward than showing up to a new table, introducing yourself, and immediately scribbling notes about someone else.
This is just one subtle but, at least for me, significant asymmetry between the seated and rotating groups. It is overall much less awkward to remain seated, I would suppose, and it is thus probably easier to make considered, discriminating judgements. In my own case I know that I probably checked off a few more numbers than I would otherwise at the end of the evening, simply because it was hard to remember enough of my impressions to make choices. As a man, I expect to be making the initial contact with my matches (and apparently the women generally shared this assumption about roles) so there was little risk of awkwardness in getting matched with someone who on further reflection I didn't really want to see -- I could simply not follow up.
I recently found an article in the New York Times that talks about a speed dating study that is going to be published in an upcoming issue of the journal Psychological Science. Given the usual state of science journalism, the fact that the article includes links that let me find a press release about the upcoming paper and a 20-page PDF file containing the paper itself was very helpful.
According to most studies and in accordance with popular stereotypes, men are normally less selective than women when it comes to evaluating potential romantic partners - in general, it appears that men are more likely to want to date any given woman than women are to want to date any given man. In a typical speed dating experiment, men and women rate potential partners as either a "yes" or a "no" depending on whether or not they want to see that person again. Men almost always rate a larger percentage of women as a "yes" than women do men, and, according to this paper, this is a fairly robust finding that generalizes over many different contexts. The usual explanation of this phenomena is based on evolutionary psychology: a female has a lot more to lose from a bad mate choice than a male does. If there were a biological, genetic basis for this tendency, it should be difficult to come up with an experimental setup in which women are less selective and men are more selective.
However, that's not the case at all. This study demonstrates that a small, seemingly trivial change in the speed dating ritual results in a (partial) reversal of the normal results. You see, in practically every speed dating setup, when it is time to interact with a new partner, men physically leave their seat and move to the table where the next woman is sitting, while the women remain seated and wait for the men to approach them. The authors of this study had the men remain still and had the women change seats, and found that this was all it took to wipe away the usual pattern: when the women were required to physically approach while the men remained still, the women became less selective then the men, reporting greater romantic interest and "yes"ing partners at a higher rate. "Rotaters" also reported greater self-confidence than "sitters", regardless of gender.
I suggest that you go read the paper, or at least the press release, yourself; my summary doesn't really do it justice, and I'm leaving the implications for the evolutionary psychology-based analysis of gender as an exercise for the reader.
EDIT: Having had some more time to look over the study, I think I should point out that it wasn't a complete reversal of the usual gender behavior: female rotators were only moderately less selective than male sitters, while male rotators were significantly less selective than female sitters. (Sitters of both genders were equally selective.)