ST. PETERSBURG, RussiaCram yourself into an airport at this time of year and you’re instantly reminded that the hottest sector of the entertainment business is still travel. The recession kept butts off planes in 2008-09 but there will be about 5% more travelers out there this summer trying to have a good time without getting fleeced. And tourism marketers are as shrewd about their product as movie marketers, even though the confusion factor of the London Olympics (July 27 is D-Day for the opening ceremonies) still has them stymied. London is either the place to be or the place not to be near, and Londoners feel the latter. Here in St. Petersburg, the young Russians who crowd the anti-Putin rallies are puzzled why stolid Westerners still pay to poke around Russia’s imperial palaces, as though the 99% are fascinated to see how the 1% historically lavished their money. My young guide at the sprawling Hermitage Palace of Catherine the Great was eager to remind her posse of tourists that the Russian empress (who was, of course, German) was a brilliant innovator at stealing art treasures from around the world. In terms of sheer box office, her museum has been packing them in since 1852. Catherine would not say, “Get me a Rembrandt” but rather “Get me every Rembrandt and then build me a replica of the Vatican to exhibit them.” The Russian army managed to follow Catherine’s lead, systematically grabbing art treasures from Germany and elsewhere in Europe to add to the Hermitage collection. While older travelers venerate the trappings of the aristocracy, the younger generation seems fascinated by their foibles. The Swedes have done a great marketing job on their bizarre Vasa Museum, a vast structure devoted to displaying the idiocy of Gustavus Adolphus. The king designed a gorgeous battleship back in 1628 that sunk within 18 minutes of its launch. The Swedes were smart enough to figure out how to pull it up a few years ago for all the world to see, and the vast museum is packed. Younger travelers still stream into Tivoli Gardens, the wondrous Danish Disneyland that has been a showcase for entertainment (it even has Pantomine Theater) since 1843. Everyone from Sting to the Beach Boys has played the Tivoli, which still, as Walt Disney remarked, seems “happy and unbuttoned” (his phrase), while the Paris Disneyland remains too buttoned up. Another megahit attraction for younger travelers is the bizarre Miniatur Wunderland in Hamburg, a vast warehouse packed with tiny replicas of every form of transportation. Having survived nightmarish airport crowds, the last thing I’d think tourists would want to see is a miniature airport, but the museum’s displays of planes, trains and automobiles — all in gorgeous miniature — are packing them in. To be sure, the differences between the habits of younger and older travelers are magnified by technology. The seniors still rely on travel guides and word of mouth; the kids are working off their apps and their multiplicity of sites like Smarter Travel or Hotwire, which supposedly will not only focus on the best deals but also the precise moments when to pounce. Catherine the Great didn’t need an app to help her create the amber room of her palace. She just instructed an aide, “Buy all the amber in the world, and what you can’t buy, steal.” Of course, the Nazis later stole it, whereupon the Russians stole it back. No regime these days wants to lose a good tourist attraction.