It involves a door an egg and 1 victim.
Step 1: Materials
Note- chose a victim that has a sense of humor, not someone who will never forgive you (i.e. Grumpy from Snow White)
Step 2: Execution
You: Hi John(victim)
John: Hi Joe(you)
You: hey John i would like to show you a magic trick.
John: why sure Joe.
You: Okay it goes like this. I am going to make an egg disappear.
John: No way! This I must see.
You: Just put your Thumb and Index finger through the crack between the door and its frame.
John: In-between the hinges?
You: Yes. Now that you have done that, hold on to this egg and look away.
John: Okay, done that, now what?
While "John" is looking away leave or just sit-down nearby and watch as he/she tries to get out of the "trap" without breaking the egg. They can't! unless you help them out of the Gag or their arms are like elastics and can stretch they are pretty well stuck there. Well at least until somebody gives in and they drop the egg or you give them a helping hand.
Note: Remember to assure them that you wont crush their fingers in the door. I also recommend that you do this early in the morning before they come to realize its April Fools Day!
Step 3: Finished
John and Joe: HAPPY APRIL FOOLS DAY!!!!!!
Note; WATCH OUT- they may be craving payback after such a devious yet harmless joke. Have Fun! :D