How do you convert an arbitrary video file into a playable Flash video using freely available programs and methods? After close to an afternoon of searching, testing and head-scratching, I finally have a whole answer that can be applied ad-hoc to almost any video you can get your hands on.
This "guide" (more anecdotal than how-to) assumes knowledge of video encoding basics, I'm not going to cover the difference between container and video formats or how to use VirtualDub, there are plenty of other tutorials and guides that cover those topics.