Rip a Streaming File with Firefox
Download or launch Firefox 3.5 or newer and download Video DownloadHelper 4.6.4 or newer and follow the instructions.
Navigate to your favorite streaming site such as youtube.com and click the dropdown menu arrow to the right of the linked red, yellow and blue orbs. It will list what files are available on this site for download.
If the site is more ornery and causes the colored orbs to grey out and go inactive, consider this: load the page with the file in question but begin the download while the video is in the early stages of caching. This may trick the server into allowing the transfer.