Rabbi Ginsburg talks about Jews and Valentine's Day.
He also has this great entry on the topic at his blog.
Although, I must say I agree in a large part with the Orthodox rabbis. After years of boycotting it, we're now trying to create our own celebration that focuses on telling our family we love them. No shiny jewelry. No boxes of chocolates. No flowers will be sacrificed in our honor. Instead, we just want to see the day the way we (or at least I) did back in first grade.
It's not questionable Christian saints and diamond rings. It's coloring pages and cupcakes.
And yes, the cupcakes still exist (in their pre-baked form). My willpower has thus far, won out in the battle for the cup cakes. :-)