Most times, you can punch in a URL then type /404 and you will get that sites 404 error page. Here are a few spoofs I've found: (Please look carefully.)
Bush's Evidence of Weapons
An actual homepage
A 'personals column' for web code
Online a lot?
The only creative ACTUAL 404 I've found belonging to a NZ website is from Greenpeace, bless em.
If you find any others, please put your comment below!
Need a better 'auto-away' message for your email? See zirconiag's blog.