By Monty Python’s Terry Jones, no less!
A couple of other favorites:
A darn cat takeover of Mouse Guest Weekly- I assume this is an April Fool: Cool Garfield MP3 Player. Cool? Garfield?
- And two by Google. Say what you want about them, they do have a sense of humor — beyond their China policies:

April 1, 2008 at 2:14 pm
Honey, can we get a flying penguin? I want a flying penguin, PLEEEEZE!
April 1, 2008 at 2:16 pm
Let’s get two. I’m hungry.
April 1, 2008 at 8:15 pm
Hey, you’re a vegetarian. I’m telling!
I enjoyed Google’s new Gmail Custom Time.
http://mail.google.com/mail/help/customtime/index.html