Microlayer films are stacks of think extruded layers of plastic materials which can impart unusual properties to an object or a package, including iridescence, mirror-like properties, and high strength. Microlayers are used in some Nike shoes (e.g., the Air Max 360) to provide elastomeric barrier films for air bladders, keeping the air contained much longer than would be possible for most single-component materials. Microlayers add security against thieves in windows reinforced with 3M's Scotchschield® Ultra films. A variety of perfume containers and other packaging have beautiful iridescent coloring from microlayer films. And these are just the beginning of the many applications.
A great article reviewing the potential of microlayer films is "Microlayer Films" New Uses for Hundreds of Layers" by Jan H. Schut in the March 2006 edition of Plastics Technology.
I would encourage you to think creatively about what this versatile technology can do for you and your product ideas.