It's no mystery why kids prefer to carry back-breaking packs over their shoulders even though wheeled bags have been around for ages. Packs with wheels either don't work very well because the tiny wheels are a mere after-thought, or are just too reminiscent of old lady grocery carts. The creators of Zuca bags set out to solve these problems of style and function and came up with sporty-looking, stout bags on over-sized, silent scooter wheels made to navigate "extreme terrain." The lightweight aluminum frame is designed so that you can sit on top of it, the wheels have flashing LEDs for night visibility, and the interchangeable bags are water-resistant and washable. Available in 8 different styles, for $119.95.