To answer the question, I don't know of any programs that will do that reliably. But there are a couple of possibilities that could work for some swfs.
1. File Juicer can extract movie data from swf files. This will only work if the movie data is in a standard format, like MPEG.
2. QuickTime Player (Pro version). QuickTime can open some older-format Flash files, although as of version 7, QuickTime Player needs a little hacking to get to accept swfs to be dragged onto its icon. I posted a how-to on this a while ago. If you can open the flash movie in QuickTime Player, just use its standard exporting options. Naturally this doesn't work well for interactive movies. If you don't have QuickTime Pro, you might be able to use a third-party QuickTime program like QTAmateur, but I've never tested this myself.