YouTube Favorite Exporter
YouTube Favorite Exporter connects to YouTube and downloads all of your favorites into a file using the Netscape Bookmark File Format. It's built using the Google data APIs.
Here's what it looks like in action -
When complete, a temporary bookmark file is created and opened in your browser
The source looks like this -
The file can be imported into Chrome, Firefox, Internet Explorer, Delicious etc.
Try it for yourself
.NET Framework 2.0 is required.
Source code now available on Github