Before the belated invention of wheeled bags, folks used to tie their bags and boxes to chrome wheelies with bungee cords. (Remember, back in the days when only nerds hooked their backpacks over both shoulders?) In the years since, teachers, and then kids, have been using wheeled backpacks and briefcases with abandon. Now, according to the NY Times, the rest of the teen and adult world is coming around -- fashionability be damned (in some cases):"When I suggested to my teenagers that they switch to backpacks with wheels, they looked at me as if I had suggested a return to Barney lunchboxes,” says the Times article. And later: “Why do preschoolers need Dora the Explorer backpacks anyway? What do they put inside? Their quarterly earnings reports?