@Fa5t3r - It really depends on the person and on what they are looking for. If all you are looking for is a few good stories, then traveling around as a tourist is just fine.
If you're really looking to change the way you see the world, then you'll have to plan harder and perhaps completely re-evaluate the way you travel.
I think people do much better when they travel with the intent of helping others, or maybe doing something like a meditation course or some other kind of learning.
The thing is, those things can be done in your own home town as well, so for some people the journey doesn't have to be done in a car or a plane.
But, for others, leaving behind what is familiar and safe can be a completely life changing experience. I know that I didn't really feel like I had left childhood behind until I traveled by myself. I wasn't trying for any kind of enlightenment, but just the experience of being solely responsible for my own well-being and safety helped me to see myself in a new light.
Your spiritual journey is always going to be personal.