Below is the code for my grease monkey script for generating links to porn videos on ExtremeTube. With this you can download the FLV videos which the website does not generically allow you to do.
You will need to install Grease Monkey to use this, which is a plugin for Firefox. I have not tested this script in any other browser.
Grease Monkey : https://addons.mozilla.org/firefox/addon/748
Script at Grease monkey depositary : http://userscripts.org/scripts/show/66261
Code at Grease monkey depositary : http://userscripts.org/scripts/review/66261