I think it's a bit like a card trick. You tell everyone to think of a card and to keep it in mind. You go through the pack and pick out their card. If you have 52 people in the audience, chances are that at least one person thought of that card.

__________________
"I am so smart! S-M-R-T!" - Homer Simpson

The sun is gone, but I have a light - Kurt Cobain

~I love Nikki~