How do stars celebrate Valentine's Day? With kisses, sweet moments with their loved ones, and sometimes matching socks! Famous folks took their V-Day joy to Instagram today to spread the love to their followers. James Franco made a special valentine collage for his single fans, while Hilary Duff went on a vacation with her son, Luca, and her ex, Mike Comrie. Keep reading to see more social snaps from our most romantic holiday, and be sure to check out how nonfamous Parisians celebrated Valentine's Day with a massive, kissy, flash mob!