Got this off a fight forum I go to. Never tried it?
Lately videos have been getting removed like crazy from YouTube and other video sites for having UFC/Pride/other copywrighted content & once they are gone you dont see them again unless someone else had the original to re-upload. I am sure some of you are thinking, "YouTube & Google Video let me download their videos already". Well, they don't really. YouTube forces you to download a flash file with their player and links and what-not, not the pure Flash Video file. And the Google Video format (which also forces you to use their player) is actually just a reference to their online video, not the video itself. Here is a short guide on how to save the real videos to your computer.
First off, the videos are converted to .flv (Flash Video) format when you upload to any of the video sites. You need to get a Flash Video player in order to be able to view the videos as programs like WMP, Quicktime & Real Player don't work with the format. I personally use FLV Player 1.3.3 found on download.com but you can Google dozens of different players.
Now that you have the player and you are ready to play any Flash Videos you download. There are 2 quick ways to retrieve the file from sites like YouTube, Google Video, etc. The first method involves using the FireFox Web Browser along with the GreaseMonkey FireFox Extension that will let you install scriptlets to automate certain processes. Scriplets for YouTube, Google Video & DailyMotion can be found on Flash Video Resources. What these scriptlets do when installed is automatically detect when you are watching a video on YouTube, Google Video or DailyMotion & they add a link to the page with the direct download link to the .flv file. Download it and you're set!
The second method is slightly more tedious & is also available on Flash Video Resources. It supports YouTube, Google Video, DailyMotion & also MetaCafe videos! When you go to the site there is a Downloader that will let you enter the URL to a video on any one of those sites (there are examples shown), and it will automatically forward you to the download URL for the .flv file. Once again, download it and you're set.
Flash Video (.flv) may not be the best quality video but it downloads and streams faster than any other format. Lemme know if this guide worked out for you.