I spotted via a Google Groups forum thread posted by Pamela, a Google Maps engineer, that Google Maps had their own April Fools joke. I did not see this posted anywhere else, so I figured I make its own thread.
Pamela said she "put together a quick mashup to let you position a "trick" over someone's home." It is pretty cool, check out this link to create your own. Here are three samples over New York's Manhattan.
A Sinkhole over zipcode 10025:

An earthquake over most of NYC:

My favorite is the alien bug over Manhattan:

Why is it my favorite? Because this actually did happen on September 28, 2006. A bug got caught in the satellite lens and it appeared to spot an alien bug on Google Maps. Too funny Pamela!
Forum discussion at Google Groups.

Comments:
seo
04/03/2007 07:01 pm
Look http://seoses.blogspot.com/ Funny Google Map pictures :)
George Byron
04/04/2007 07:27 am
Pardon, but have you ever heard of (really existing) space bugs? I doubt so. "A bug got caught in the satellite lens" doesn't make any sense and is rather funny. The bug got caught in a scanner (on earth), not in a satellite lens (in space). Furthermore: try photographing with a zoom lens and put a bug onto the lens. You will not be able to see more of the bug than a blurred dot.
Ralph Nudi
04/20/2007 02:02 am
Those are great. I am going to look at areas over Kenosha, WI