Just a normal deck of cards.
In this trick, you will surprise you friend/victim that you can find their card out of all 52 of them! (Remember not to see what their card is, you aren't suppose to in this trick)
Step 1: First Thing
Shuffle the deck to make sure they know there's nothing set-up (really, there isn't). Spread the cards, either in your hand or on a surface, and tell them to select one.
Step 2: Second, Most Important Part
Now, this is the part you have to do, and is very important or otherwise you will look really retarded in the end. Split the deck with your hands and have each one in both different hands. Tell him/her to put the card back on top of the one facing down. IMPORTANT: Look at the other deck at the card facing up, you need to remember that! Make sure you try not to look at his/her card, or don't let him/her think you are.
Step 3: Final Step
Now, instead of look for their card, look for the card you we're suppose to memorize, which would be the Jack of Spades. The reason your suppose to find the card you memorized is because that card will be behind their card, simple! So once you find the Jack of Spades, the card you memorize, look exactly one card infront of it. VOILA! Its magic (not really)! The most simplist of all card tricks, and it still surpises them!
Here's a tip to make it seem more magical. In the middle of the trick, where they put their card back after you memorized the card after it, tell them to think of their card, to pretend to 'read' their mind. Then, once you look for their card, they might get more of a kick out of it!