Instructables user mygibzone gets thirsty, which is why he came up with a way to keep his favourite beverage mixes in a wristband so he can have a drink by just adding hot or cold water. Here's how he does it.
What you're doing with this bracelet is making plastic tubing long enough to hold enough concentrated drink mix to make one drink, then disguising the bracelet so you don't look like a weirdo that's wearing plastic tubing around his wrist. Mygibzone offers you one method of making the bracelet, but you should feel free to come up with various styles to suit your fashion sense.
While having drink mix concealed on your person isn't useful for most situations (just take a thermos to work), it can be handy for places like sporting arenas or prisons, where you get searched on your way in.