After extensive research, I have figured out two possible routes to becoming a Disney Imagineer, what has to be the best job ever if you're a Disney fan. Both plans involve lots and lots of research into Disney history, as well as the ideals Disney promotes through their work.
Plan A:
1) Be either a college junior/senior, OR a recent graduate in almost any creative or engineering/architecture-related field.
2) Gather a team of like-minded fellow college students/recent grads and enter the Disney
Imaginations contest.
3) Get lucky,
Plan B
1) Take any Disney job you can get, even if it's street-sweeper after hours.
2) Create, create, create.
3) Manage to show your plans and thoughts and creations to someone who matters.
4) Get lucky.
Obviously, Plan A is shorter by one step, but both will depend a great deal on your dedication, imagination and skill. There may be other routes, but from my research, I can confidently say that all of them will involve that grand, elusive thing we like to call "a shitton of luck."
:D