When I was summering in Europe a few years ago, I was amazed by the obstacles to traveling. They weren't the same as in the US, but they were rather difficult to overcome nonetheless. Over here we've got a problem with distance - everything is so damn far away. I can make it over to Colorado, but it takes a good twenty hours. In Europe the distances aren't so severe, but the cost of traveling is. I spent $250 getting from Arco in northern Italy to Font in central France. It was just over ten hours of driving, which I can easily handle, but I went broke in the process.
As gas prices increase, the world is going to grow. The world has been getting smaller for the last thousand years, but I see this trend changing in the next ten. With the end of the era of cheap energy, traveling will become more difficult for the first time in human history. I feel is this summer looking at plane tickets. Getting to Europe this year costs as much as China last year. It is only going to get worse, so I foresee my wanderlust becoming more and more of a burden.