You: I want you see if I am able to read your mind. I want you to think of any two simple geometrical shapes, one inside the other. Like a square or a rectangle. Don't use the square or rectangle as I just mentioned. Keep it simple. Do you have it in your mind?
Friend: Yes.
You: I am getting a Circle and a Triangle.
Friend: OMG!!! How the hell did you do that???
You just smile and walk away leaving them blown away.
PS: It works over 90% of the time and for some strange reason, people always think of the circle and the triangle ;p
Another one:
You: I am going to see, if I can catch your thoughts. To do this, you will need to keep it simple and not over-think. Tell me the first thing that comes to your mind when I ask you a question.
Friend: Ok.
You: Don't say anything out loud. Think of the name of the first vegetable that comes to your mind?
Friend: Done.
You: Think of any 2 digit number between 10 and 50. To make it interesting, make sure both the digits are different. Also, lets make both the digits odd numbers. Do you have a number in mind?
Friend: Yes.
You: I am picking the image of a carrot and the number 35.
Friend: OMG!!! How the hell did you do that???
You again simile and walk away.
Most people think of carrot as the first vegetable and most people think of the number 35 or 37 given the above conditions.
Have a blast with above and share your experiences :)