During our trip in Albania my wife and me got to talk about art and how museums tend to attract less and less people for their regular collections and more and more for special & travelling collections. Of course this phenomenon is close to not ever going to a museum in your home town (unless you have visitors) and visiting three in a weekend when you go to a foreign capital. Last chance to see attracts.
Circulate art and people will visit more. The ultimate conclusion of that, of course is to make all museums travelling circusses. One of the easiest ways to do this, might be to put the art on trains. It would also make for an interesting way to travel; you catch a train that takes an hour or so and while traveling you have a look at the collection of a museum from a completely different country. Mix the trains enough and publish the schedules including which collection is where and you have a hit on your hands.