I recently used my phone to get some pics of ESP (Zenner) cards, so I could carry them with me everywhere.
I then created an effect where The spectator looks at a pic of a hand holding a card with all 5 symbols on. They think of one (e.g. the square). I close up the phone and leave it in their hands. They name the symbol for the first time. They turn it over, and there, in full glory is a pic of a square.
The method is so simple, 100% guaranteed success. I've even tried a few different presentations too.
Using a full deck sounds quite ambitious (pun intended then instantly regretted) though. I'll be interested to hear how your effect turns out. You'll have to post a full description of the effect once it is finished.
Good luck
