Are you sick and tired of getting the "this video is no longer available" message on Youtube? I found this trick that works in most cases.
Append the end of the URL with this string:
&fmt=6
or
&fmt=18
So, if you have
http://youtube.com/watch?v=x0otD2GQE7k&feature=dir
and it doesn't work, try:
http://youtube.com/watch?v=x0otD2GQE7k&feature=dir&fmt=6