Torsten Adair says:

My favorite is the BBC’s report on the Swiss spaghetti harvest.
(And speaking of the date stamp, MySpace lets you set the date on your journal postings.)

Christopher Moonlight says:

My father is going mad today, over his mother flying in from France, so I told him that all of Air France’s flights had been grounded for the next week. I’ll be watching my back for the rest of the day now.

Torsten Adair says:

And the ever popular office prank where Ma Bell will test the phone lines by sending water through the system, so please seal your headsets with plastic to avoid any leakage.
Another favorite is giving your secretary a clear plastic floppy disk sleeve, telling her that if she puts it on whichever disk she is using, it will prevent computer viruses!

For those who enjoy such things:
http://www.museumofhoaxes.com/hoax/aprilfool/

And I recall Marvel Age mentioning in their history feature an early 1970s Avengers story drawn by M.C.Escher…

maija says:

I liked this:
http://books.google.com/

And this is strictly awesome:
http://www.youtube.com/watch?v=nrxmpihCjqw

Peter Krause says:

I’m sending this response email from April 1, 2015…but you’d never know it!

Oh, by the way, the Cubs win the 2009 World Series, and beware that stock market crash in October, 2011.

You heard it here first!