Hi,
I've been using kickyoutube.com so far to download YouTube videos. Unfortunately sometimes it isn't always very responsive and it displays a loaded page. But then I remembered that you can bookmark JavaScript code.
⚫ You only have to bookmark the following code as if it were a normal URL:
⚫ Then you open a YouTube page and just click the bookmark item - browsers display them in various ways.
⚫ Alternatively you can always paste the code in the URL bar and run it there (on a YouTube page.)
Tested in Opera 9.6 and Firefox 3.