There are plenty of variations in reusable water bottle designs, but none quite like the Solar Waterbag! The flexible, filled bag is made to unroll, flatten and be placed in the sunlight to warm the water. Why this athlete in the photo is chugging warm water while exercising remains a mystery, but it seems like a great idea for camping! Designers: Furong Zhang, Yuqian Jin, Hengchang Su, Jianzhuang Tian, Song Qiao