Make a Remote Mac SingI found this at http://lowendmac.com/crews/06/0110.html
This one requires you to have a administrative login account on a remote Mac that has Remote Login (SSH) enabled. Assuming your friend or co-worker's Mac meets these requirements, you can play a heck of a April fool's joke.
In the Terminal, first remotely login to the system by using ssh <username>@<remote Mac's IP address or hostname>.
Once logged in, enter this command:
sudo osascript -e "set Volume 20"And then press return. This sends an AppleScript to set the volume to an audible level. Then enter the following command:
sudo osascript -e 'say "Dum dum dum dum dum dum dum he he he ho ho ho fa lah lah lah lah lah lah fa lah full hoo hoo hoo" using "Cellos"'
This sends an AppleScript to say the phrase using the Cellos voice. The results are quite humorous. You can try it out on your own system to hear what it sounds like.