On The Jerx (previously), "Andy" describes a fantastic magic trick that you can only pull off under very special circumstances: a day at the beach.
The effect: after a day's playing by the beach, wearing nothing but a bathing suit, you walk down to the sea with a child's sand-pail, and return with a bucked of sea water. You pour out a cupful and hand it to a bystander, inviting them to try it. As the spectators exclaim that you can't drink sea-water, you reach into the bucket and bring out a handful of white, sparkling salt, explaining that you're going to desalinate it before drinking. You set the salt down. Then you make kool-ade with the remaining water, right in the bucket, and drink it. The kool-ade is delicious, made with fresh water. The water in the cup is seawater.
The trick has been done before — it's a variant of Sands of the Desert, popularized by Doug Henning. How the trick is done is less interesting than why Andy suggests doing it his way, rather than Henning's, which is a neat encapsulation of the basis for "audience-centered magic."
Look where we are. You got water from the ocean. You set some of it aside which anyone is free to taste. Someone has reached into the bucket and found nothing but water. And now you're in that same beautiful position from the original Sands of the Desert routine. With an absolutely empty hand you reach into the bucket. (Tip it towards them so they can really see your hand enter and exit the water). You come out with a handful of clearly dry "salt" that spills from your fingers. It's perfect.
They can taste the water to see that it's now fresh. If someone wants they can taste the sample that was set aside and find that it really is saltwater. And then you make some Kool-Aid. (I actually came up with a way to de-Kool-Aid the water too, but it's overkill.)
The Sweetness In Water [Andy/The Jerx]