Tried to find it, but unfortunately the video link is dead:

  http://www.creativityworldforum.be/view/nl/6432289-Sessions.html#session1

There is a PDF though with a bit more background:

  http://www.flandersdc.be/static/content/CWF08-day1-John_Cleese.pdf

Some of the other talks at the Creativity World Forum look interesting too. Steve Wozniak's talk, for example.

The Cleese video is down, but many of the other videos, such as Wozniak's, are still up.

EDIT: It appears all the videos on the site are abridged. The Cleese talk on Youtube is probably the same as appeared here before the video was removed.

I think the abridger did Cleese a favor, there. The talk seems a bit light on ideas.

It doesn't appear to be available, but there are some other interesting Cleese talks and excerpts on the topic of creativity:

http://www.cornell.edu/video/?videoID=475 http://www.youtube.com/watch?v=WuzIu62xswg http://www.youtube.com/watch?v=0yyUhlaSJ28