Many sites have good .flv video content that you would rather download and listen to when you are not connected to the internet. Firefox plugin called the Download helper makes it easy.
Just follow the steps
Not sure if it’s legal, but you can:
– with Firefox
– and DownloadHelper extension
– click Play once, so that DownloadHelper can see the video
– then download it with DownloadHelper
As soon as the download helper, sees the video, it would give you an option to download it!