watch them on youtube...then get file from temporary file
remane it with any name and at the end make it like this example.flv
.flv in end.....now its an flv file...u can play with flv player
then download free flv player from here
http://www.download.com/Free-FLV-Converter/3000-2194_4-10832044.html
and convert to mp3...and rock on.....no need to visit any sites