Credit cards are useful for lots of things: paying for groceries; proving your identity; breaking and entering. But what do you do with the expired ones (besides using them for breaking and entering)? For the past few years, designer Kelly Campbell has been cutting up old credit cards and turning them into colorful jewelry: chunky bracelets, funky necklaces and dangly earrings made from circles punched out of an old MasterCard or long plastic strips sheared from a spent Starbucks gift card. The result is whimsical and stylish, not to mention earth-friendly. Go ahead, charge one.