ranco Dragone, the director, gave Cirque’s next smash hit its one-letter-name because it’s a symbol for infinity; moreover, “O” is the phonetic pronunciation of “eau,” the French word for water. Go to see O, and turn your attention from the stage for a moment and you’ll find another reason for this odd-title: the saucer eyes and open mouths of the audience. This is simply the most astounding, profound, exhilarating, eye-poppingly beautiful show in Vegas. I know that’s a long chain of superlatives but if I had more space, I’d probably add a couple more. The show is centered around a 1.5-million-gallon pool, an engineering marvel: In seconds flat it transforms from pool to a shallow African watering hole, to a dry platform filled with dancers and acrobats, to a plateau with dancing fountains, or to a shimmering lake studded with islands and clown-steered houseboats. Synchronized swimmers plunge into its depths, staying submerged for what seems like ten minutes while above-the-water divers twist and knife in, as brilliantly costumed parades traverse the edges of the water. It’s a spectacle like no other and does the impossible: It tops all of the other brilliant Cirque shows. Performances are held Wednesday through Sunday at 7 and 9:30pm.