Effect

The mentalist asks a mobile phone to a spectator, announces that it is going to make a search on internet and once is done, leave the phone on the table
asks the spectator if he had to find something on internet, that would look for and where you do it? The spectator named for example on a map and look for the city of new york...

Under these conditions, the mentalist ask the spectator to take his mobile phone and look which was the search done
Under such conditions, the viewer will find a search in google maps with new york city selected. The spectator could have named any city, but nevertheless, the prediction will always be 100% correct.