Ice cubes - enough to fill the entire drink container
A large drink dispenser
(Either in a Glass or a drink dispenser) Fill the glass or drink dispenser with Ice. Pour in the Cranberry Juice. Next pour in the Blue Gatorade Frost, BUT make sure that when you're pouring the Blue Gatorade Frost that you pour straight onto some of the ice to gently add the layer. If you pour it directly into the juice it will mix! Next, pour in the Diet 7up, also pour onto an ice cube to prevent them from mixing.
I suppose you could do this with any color drink combo.
You need to use drinks with varying amounts of sugar, since those that contain more sugar (such as soda) are denser than those with less (such as diet drinks), this makes it possible to actually stack one on top of another.