Walk into Let's Scrap! on any given day and there they are: mesmerized kids measuring, cutting, gluing, painstakingly putting together pages of photographs, text, stickers, paper cutouts, ribbon, glitter. Filling volumes that document almost every stage or event in their still-short lives, the little ones are creating scrapbooks, a grand tradition they've now dubbed "scrapping." It's a task that requires hours of rapt attention and careful labor, hours that could occupy your children and give you that much-needed time-out. Albums, paper, scissors, glue, and all the decorative doodads can add up to real money, but scrapping is priceless: a creative, constructive hobby that keeps youngsters away from the potentially negative (as in brain-dulling) influences of TV, video games, or the Internet, and safely removed from possibly bone-breaking activities such as extreme sports. Good news for kids who aren't very crafty: Monthly classes cover chalking, stamping, and picture tinting. But the best news for weary parents at the end of their rope: Mastering the finer points of scrapping takes a really long time.