Locate by Geni (original download , no watermark)

Start with a borrowed shuffled deck, spectator freely cut the deck into 3 piles and choose 1 pile for them. Take a look at the top card and take that pile face up sandwitch between the other 2 face down piles. They riffle shuffle the deck, face up and face down cards mixed together. Now just take about less than 5 seconds, you can find out what card they choose.
+ No gimmick
+ Easy to do