If you are one of those who like to play pranks on your friends but also know the limits to which the prank can be pushed to, then PeterAnswers is the best computer prank ever.
The Website peteranswers.com calls itself a virtual tarrot and gives your friends a complete feeling of something from the parallel world. There is an input window with two fields on it as shown in the pic below.
The first one is a petition, where you write "Peter, please answer:" or "Peter, please answer the following question:". In the second field is the question that you want to be answered like "What is my best friend's name?".
Your friends would be amazed that peter goes on answering your questions with exact accuracy. But, when your friends ask the question, it gives random answers like "You need to trust more". You can ask your friends to keep on asking until peter believes that you trust him and then he'll start answering them. You can also tell them that it took you 4 days to make peter trust you.
Here's how it works -
While writing the petition, your friends do not know that you are actually feeding the answer to the question you are about to ask. Take an example.
Your friend ask tells you to ask peter the colour of your t-shirt. Here is what your friend sees n the screen.
Petition : Peter, please answer:
Question: What is the color of my t-shirt?
You feed your answer while typing the petition by just hitting FULLSTOP or '.' and feeding your answer then again hitting FULLSTOP or '.' The computer screen does not show what you are typing. It goes on writing the petition. Consider the petition in the above example.
Computer screen shows : Peter, please answer:
But you actully typed : Peter.yellow. answer:
So you just fed the computer with the answer you are expecting. Now you know how to do it, go on and make your friends crazy.