just use youtube-dl to download the file and then play it with vlc,
mplayer, xine, etc

$ youtube-dl http://www.youtube.com/watch?v=boCRch_9R1Y
[youtube] Setting language
[youtube] boCRch_9R1Y: Downloading video webpage
[youtube] boCRch_9R1Y: Downloading video info webpage
[youtube] boCRch_9R1Y: Extracting video information
[download] Destination: boCRch_9R1Y.mp4



-- 
Kathryn
http://womensfooty.com
US Freedom Signup: http://womensfooty.com/freedom/2011