The History Channel has videos and more about not only the history of Valentine's Day but also games, romantic quotes and a ranking of the top romance movies of all time.
Wikipedia also has an extensive page discussing the history of Valentine's Day and facts about how Valentine's is celebrated throughout the world.
U.S. Census Bureau Press Release has facts and figures analyzing Valentine's Day- for example, how many single men are there in the U.S. who are in their 20s for every 100 single women of the same age.
CARDS & MORE-
Collection of Vintage Valentines, from West Virginia University Libraries. Images can be send as greeting via e-mail.
Mount Holyoke College Special Collections is presenting an online exhibit of valentine cards from 1899-1935.
National Public Radio has pulled together an assortment of news stories and features discussing Valentine's Day and the people that either love it or hate it.
And e-cards are everywhere - Hallmark, American Greetings, Yahoo, even the CDC has a way to send greetings for Valentine's Day.
Happy Valentine's Day!