The pair, undergrads at Rensselaer Polytechnic Institute, introduced their idea at last month's March Madness for the Mind, an expo run by the NCIIA. They've produced several bottles so far on rapid-prototyping machines, and have done computer simulations to show the variety of structures that the bottles could support. Next up: Trying to get funding to mold their bottles on the same machines that real manufacturers use. "One of the benefits of the design is that it fits in today's standard processing," says Naples. Manufacturers wouldn't need to change equipment, shipping methods, or vending machines. "Anywhere you see a bottle today, it'll still fit into size and shape constraints."