Capture Streaming FLV to Disk

I can watch streaming video from flash website (FLV format) using Firefox and adobe flashplayer 7.
Example: youtube.com

I plan to capture the streaming flash video into hard disk.
How to do this operation?
Is there any firefox / mozilla flash capture extension for Linux?

Thank you.

Try this firefox extension - VideoDownloader

Thank you for the reply.
On some videos, user have to login to view the video.

This video cannot be downloaded using downloader extension.

You should use "GreaseMonkey" extension and a special script for Youtube.

http://www.lifehack.org/articles/lif...ey-script.html

There will be a red link on top of the page.
Click on the link and wait for several minutes.

i just found this awesome kommander script called FLVGET

(personally i prefer REAL programming 'C with GTK' rather than the slowest interpreted RAD envirment that is kommander. although i do respect its ability to create completly script based gui appz that fit right in with KDE and require absolutly no computer programming knowledge)

FLVGET downloads the FLV video and then converts it to AVI with ffmpeg (faster then you would think)

i really hope one day this AWESOME script becomes a real slim GTK app done in C, then it would get a package and rock and roll!