This one happens FASTER than the blink of an eye!
Fill a small glass full of liquid (yes, real liquid!). Hold the glass in your outstretched hand, placing it in full view on your palm. Cover the glass with your other hand- and then SQUEEZE your hands together- SQUASH! Your hands push flat together because the glass and the liquid are GONE!
No spills! It's self-contained! (You do have to wear a jacket, though).
This is so good that a famous magic company built their business selling this one trick!