Salon.com is featuring this link to the multimedia magazine GOOD and its examination of the subject, which itself is a video riff on the recent study The Science of Kissing: What Our Lips Are Telling Us by Sheril Kirshenbaum.
(Talk about derivative.)
Nonetheless, it's a compilation of most kisses-on-video you might care to see.
My favorite factoids:
-- Around 90% of the world's cultures kiss and 2/3 of us tilt our heads to the right.
-- A kiss can be 10 times more effective than morphine in reducing pain.
-- In the Middle Ages, illiterates could seal legal deals with an "x" and a kiss ... which is how the kiss got its "x" signature.
-- Passionate kissing burns 6.4 calories per minute. 1 Hershey Kiss = 26 calories. That's a 4-minute kiss.
-- When people kiss they exchange between 10 million and 1 billion bacteria.