From Tokyo's fashion-forward Shibuya district to New York City's SoHo, the must-have accessory this year is the lucky charm. Prada charmed the front-row crowd at last month's fall fashion shows with miniature leather handbags dangling from purse straps. The Gap sells plastic and enamel flower charms for $5. "It's a way to personalize your bag," says Emma Hill, vice president of adult accessories at the Gap. "I always have all manner of bits and bobbles hanging from my bag, and I can change the charms instead of changing my bag." Recently charms have been migrating to mobile phones, and luxury-goods companies like Celine, Bottega Veneta and Louis Vuitton are joining in, creating tiny charms that can be looped onto your cell with an elastic band. Celine's charms look like jewelry and feature the house's interlocking-C logo, while Bottega Veneta has come out with Lilliputian animals in leather and crocodile.