zhusee2 / YouTube-video-downloader-for-Safari

A Safari 5 extension that adds download links to YouTube video pages. It uses no other sites—just YouTube and the extension.

Installation and use:

1. Download the .safariextz
2. Double click it, and choose "Install"
3. Go to any YouTube page
4. Click the new "Download Video" button
5. Option-click on any of the available formats