Looking for a way to bring the true spirit of April fools day to your office? The folks over at RJL software have an amazing collection of free Windows applications you can download onto a co-workers computer to celebrate the greatest holiday of them all.

These are downloads so make sure the person you're pranking is someone who will receptively accept the joke otherwise you might find yourself on the post-holiday unemployment line.

Here are some of out favorite programs for the big day:

Random Burper: The name says it all. This hidden program burps at random intervals until it's closed. One cool feature of this app is that it gives you the ability to control the sound on the computer specifically for the burp that way you can make a burp play super loud and then have the sounds on the computer immediately return to a normal sound level. Fantastic.

Vista Upgrade Prank: This fake Windows Upgrade Advisor appears to install Vista onto a computer but will instead display a Mac OSX desktop with a little Vista flare.

Clippy: Clippy is gone from Word which means he has tons of free time to prank your friends. Clippy pops up in the lower right hand corner and gives out important facts such as "Your computer seems to be turned on" and "I noticed you have Internet Explorer installed on you system. You can use that to find things on the Internet."

Finger: Ah, the finger. The finger takes the traditional pointing finger cursor and has it umm...give you the finger every 5 seconds. Advanced finger users can specify the delay between flips.