Converting Video Into Audio

What is the easiest method of using a video player such as youtube and converting the music from the video into an audio file say a wav file without the use of a mic? is there an freeware out there that you anyone knows of to do such things? cheers

ffmpeg -i m00vi.flv soundtrack.wav

MediaCoder is a really great freeware app that can transcode a ton of different formats:
http://mediacoder.sourceforge.net

I use it pretty often.

Edit:
But yeah, you’ll obviously need to grab the video itself first. Look on Google for the many ways you can do this:
http://www.google.com/search?q=save+youtube+videos

.

has an “audio only” option: http://vixy.net/

mplayer video.flv -vo null -ao pcm:file=audio.wav  

tho mplayer isn’t freeware ):

Well, I was about to say virtualdub till I saw you were talking about flash vids… so yah… nm :P

i use vixy to rip the video’s in general if i want an offline edition.