"Kafka" finds Steven Soderbergh following up his character-driven debut, sex, lies, and videotape, with an exercise in style that, unfortunately, displays more energy than inspiration. Still, the look of the film -- shot in black and white by Walt Lloyd, until a climactic switch to color -- is stunning. The scene is Prague, circa 1919, and the play of light and shadow on the cobblestone streets is a film buff's cornucopia of expressionistic allusions -- from F.W. Murnau's Nosferatu and Fritz…