Ipfini, Inc. has created a unique liquid container called the Choice-Enabled Packaging.
This container has "buttons" on the side of the container's surface that release additives (flavors, colorants, etc) into the liquid.
These additive buttons let the consumer choose different versions right at the point of consumption. A programmable cola bottle with buttons for lemon, lime, vanilla, and cherry flavors as well as a caffeine button allows for 32 possible choices of soda.
Link (Thanks Dorky Rooster!)