This is the method of flight mooted by Douglas Adams in the The Hitchhiker's Guide to the Galaxy series. The technique goes roughly as follows:
One falls/throws oneself/gets pushed off something, towards the ground. Then, at the moment one is about to hit the ground, one is distracted by something else, thereby forgetting to hit the ground. This, as the author of the books explains, is rather difficult to do, because hitting the ground tends to take up a rather large amount of one's concentration during the process of falling. Schools, Douglas Adams tells us, are available where sufficiently experienced tutors are available to help provide distractions at the crucial moment, or (and more often the case) characters simply end up flying unintentionally, and generally only briefly (that is, until they remember that they are supposed to be falling and hitting the ground).
This has led to a whole new school of science*, which asks the question "What happens if the mind *truly* forgets about {gravity|inertia|momentum|mass|bouyancy}? Do these laws depend on the mind (or, for that matter, some active agent) to carry them out (and which can, therefore, be fooled), or are they permanent and passive forces?"**
*Please bear in mind that this "school of science" is in no way real outside of Science Fiction, and any decent Scientist would probably laugh at you for asking this question.
**A question which The Matrix answers in a rather sideways fashion, but very well.