I am doing a story for my school newspaper detailing the history of Valentine's Day. I used the sticky post about the history and Wikipedia's very thorough page about the "holiday", as well as some other sources, for the bulk of the story. I found out some interesting stuff about the "holiday", especially how it's grown in the 20th century.
It's become a holiday of consumer goods basically. The diamond industry was facing some hard times in the 80s and declared Valentine's Day a good time to buy jewelry. This is why you see those cheesy "Every kiss begins with Kay!" commercials around this time every year...thanks a LOT for that, diamond industry.
In Asia, it's all different, though. In Japan and Korea, Valentine's Day is actually a day for women to give men chocolate. (It's basically a marketing holiday.) Because of etiquette rules, the giving of chocolate to men has become an obligation for many women. They even give chocolate to their co-workers. Sometimes, that costs a ton of money. A month later, on White Day, men are supposed to return the favor, generally with white chocolate. Men don't have to do obligation chocolate, though, they can just give chocolate to their girlfriends or wives. (White chocolate is such a ripoff! Yucch!)
There are other traditions, too, but no matter what, it's really all the same...just different names and specifications.

