Walkabout is one of my favorite films: with the sole exception of "The Rabbit Proof Fence", there is no other movie quite like it (and RPF is actually based upon a true story). There's a LOT going on in Walkabout: issues of Madness, Race, class, modernity, destiny, resignation, and much more, all instersect in this timeless film.
I have seen this movie around 30 times since it's initial release, and I pick up new things with every viewing - even better, despite this being a rather old film, it has never seemed dated in any way. Just more and more prescient.
Notable is Jenny Agutter, who is better known for "Logan's Run and "Equus", but who's "performance of a lifetime" was here in her first major film. She is a joy to watch, but she is certainly not the best this classic film has to offer: that would be the young David Gulpilil, who is an actual aboriginal, and who was completely unknown at the time as well.
Come for the Aboriginal survival story, stay for the modern teenager crush story, and watch the credits while munching on unrequited Aboriginal love!