While there are many places one can download YouTube videos for free, the last place I thought I would ever see one would be on Orkut--especially since Google has started to crack down on third party sites.
Simply called YouTube Video Downloader, this app allows you to download any YouTube video, although the format will be in .flv format (which you can convert to something a little bit friendlier with the help of Convert Direct).
Now that YouTube has (finally) allowed users to download videos (in high quality too!), I would not be surprised to see this app pulled, although I doubt that Google's lawyers will be able to go after them as the creators posted a legal disclaimer telling you not to download YouTube videos.
(YouTube Video Downloader) Here I would like to warn that NEVER DOWNLOAD ANY VIDEOS FROM YOUTUBE. THIS IS ILLEGAL AND AGAINST GOOGLE'S POLICY. USE THIS POST FOR EDUCATIONAL PURPOSES ONLY.
Exit question: How long do you think this app will remain up? I give it 48 hours. :-)