Marco's Comments:
One of the booklets prepared for the 3rd Incontro dei Mentalisti Italiani, in Padova, 16-18 April 2010.
This booklet explains a very clean version of the effect where a spectator finds the only card with a symbol amongst five, presenting a number of variations and thoughts. The method is very clever, although it could be improved (see my notes in the booklet). Very good.