The first date kiss discussion has spread to some other blogs and to the journal office. Since I have been informed that the kissing parts of my blog are the best ones, I'll weigh in further.
Phoebe Maltz interprets the kissing dynamic as consisting of a shy boy and a waiting girl. This may be a common phenomenon, but you should make your enthusiasm for further interaction clear, no matter what your sex or sexual orientation. What better way is there for Rachel Bussel to test her "straight girls don't exist" hypothesis than to give out a few smooches and monitor reactions?
The Miss Manners column quoted by Will Baude is conservative in the extreme (even I, who hate to be touched by strangers, would not find a end-of-date hug untoward), but it does reemphasize the necessity of making one's preferences clear. If you're not into physical contact on the first date, you need to substitute one form of obvious interest for another, a la Brock Sides. While a person taking Miss Manners's advice might manage to carry it off and still give the impression of wanting a second date, it's perhaps more likely that someone who jumped back at the prospect of a mere hug would be written off by the other party as uninterested. And while Will is correct to state that not everyone who walks away kiss-less should be discouraged, letting someone you're interested in walk away with no clear indication of your desire for a second date is a recipe for disappointment.
UPDATE: PG agrees that a first date kiss is not presumptuous, especially if it's a date with someone you're acquainted with already. She also brings up the very astute observation that kissing is quite safe, especially the Bamber-approved cheek kiss.
Melinda points out that a first date kiss can provide early warning of poor kiss-compatibility. Why waste time on second dates with terrible kissers? And why end a date when you could hang around and kiss for a while?