Subliminal Projection Hat

By means of a miniature led projector (link) concealed within the hat, connected to an under-brim lens via fibre optics, the Subliminal Projection Hat can overlay a stored image of your face onto your actual face for the period of 1/25th of a second every five seconds. This will go unnoticed by observers but will leave behind the suggestion of the emotion portrayed in the stored image.

For instance, when holding two aces in the hole in a game of Hold 'Em you could set the hat to fire a stored image of "Disappointed Face". This will mislead players even if you have trouble hiding your delight.

In the linked image ("Man uses Hat") a man is shown looking baffled while negotiating a complex property deal. Below this is the same man a fraction of a second later while the Subliminal Projection Hat is firing a burst of his "Aggressive Samurai Face" This will leave the other party feeling defensive whilst unable to ascertain the cause.