Continuing the Valentine’s Day theme

The Onion offers a bunch of Love Coupons. I’m particularly excited about “One sexual act completed expressly for the purpose of procreating another child of God.”

Can anyone tell me what the official origin of Valentine’s Day is? I’m finding little conclusive evidence in the Wikipedia entry on Valentine’s Day, but I get the feeling it’s another pagan holiday hijacked by Roman Catholicism and finally commercialized. In Japan, Valentine’s day doesn’t work out so well for the ladies according to the Wikipedia article. Basically the girls are expected to purchase chocolates, often at great personal expense, for all their male co-workers. They get their payback on March 14, White Day, but they only get goodies from their significant other. Harsh.