Youtube extension

Youtube extension in Firefox that allows you to save a page for upload to your browser. Select the option

Page Saved (styled underneath).

In the other side of the app, select the option of Save to cache. This application also supports saving from Safari, Opera, Internet Explorer, and Chrome. You will see the entire page if you saved it to a cache for instance.

You can also save from Picasa.

The source code is in plain English, but you can also get the source code from GitHub, which has it available as a tarball.