As you might have guessed I use some form of online services pretty much every day.
April 1'st greeted me with two stunts from services I use from google.
The first was a message in my GMail window saying "New! Gmail Autopilot" in the slot usually reserved for announcements from GMail labs about new features. When I clicked the link to check out the latest do-dad, it took me here: http://mail.google.com/mail/help/autopilot/index.html
OK, that's pretty funny. I especially liked the google auto pilot response to the Nigerian scam-spam mugu letter, then I realized a lot of new GMail users might not even know what a Nigerian scam-spam email was since GMail has become pretty efficient at filtering out this garbage. Still, a great April fool's effort.
Google wasn't done with me yet though. Next I checked my YouTube (a google owned company) account. For a second or two, everything looked normal--then suddenly the entire screen reversed. All the letters were backwards and in reverse order and the videos themselves were upside down!
Now THAT was impressive. You can't do it using regular HTML. They could only do it at all because most of YouTube is in shockwave which gives the author a lot more formatting choices.
Google has pulled April Fool's day pranks before but this year they really made an extra effort with different departments in the company offering different pranks. Besides Gmail and YouTube, Google had pranks hidden in their Analytics, gBall, Google Maps, Google Images, Blogger, Google Chrome, Google Earth, Google Code, Google Docs, Google Mobile and Knol services. I'm excited to see what they come up with next year.