Thanks

I use a freeware program called Riva FLV Encoder to view Flash video (.flv) and in the installed directory is a fantastic little program called ffmpeg.exe which runs from a command window. I use this to convert from .swf to .mpg - it also converts most .flv files as well, dependent on codec. There are tons of options too - I tend to convert the sound to stereo mp2 as it's easiest for my use, but you can use mp3 if you like!
To see all the options, just type ffmpeg by itself and they will all be listed.

Hope this is useful for you