I just saw an article about munging together a gif and jar file, which reminded me of the classic file concatenation hack. I wonder if it would be possible to create a swf and concatenate it with a zip such that both are valid. I imagine that compression in the swf would make it less easy, but perhaps still possible. And you can always turn compression off. I just think it'd be neat to make a swf file that you could also simply unzip to get the source code.