Dianyla posted this a few weeks back:

Quote Originally Posted by Dianyla
For those that don't like the taste of most electrolyte drinks, you can make your own homemade drink using Morton's Lite Salt. You can find this at almost any grocery store, it's in a light blue canister, and contains both sodium chloride and potassium chloride.

A basic recipe:
1 teaspoon of "Morton's Lite Salt"
1/3 teaspoon of baking soda (sodium bicarbonate)
10 teaspoons of table sugar (sucrose)
1 Quart of water

I believe you must have a certain amount of sugar in order to facilitate absorption of the salts, but not too much. If you decide to flavor this with something already sweet like juice you may need to decrease the amount of sugar you are adding. Google on "morton's lite salt" and "electrolyte" to find more recipes.
I tried this recipe and it was pretty dreadful (used koolaid mix as flavoring agent) but I've also tried adding the Lite salt to OJ and it's very tolerable. But someone would have to calculate if the osmolarity was right - any chemists in the crowd?