Here’s a piece of yuletide trivia: the first Christmas card was dreamed up by an art bureaucrat. It was Sir Henry Cole (1808-1882), first director of the Victoria and Albert Museum, who -- daunted at the thought of writing piles of greetings -- came up with the idea in 1843. That card depicted a merry Victorian family, flanked by scenes of charitable acts. More recent artists’ cards, on display at Tate Britain (through Feb. 1, 2010), prove that modern art can be Christmassy too...