Cloud computing and downloading have made physical media like CDs about as relevant as a pile of old 8-Tracks, but what do you do with all of those old discs? Designer Seung-il Kim says we should stack them up to make some workout weights, to burn off all that extra weight we put on while sitting around downloading stuff.
CDs aren't really that heavy with a stack of 20 discs weighing in at about 2/3 of a pound, so Seung's concept lets you add two stacks of discs on each side of a 2.2-lb handle for a maximum total of almost 5-lb per dumbbell.
For people who really want a serious workout, perhaps Seung should make a version that uses vinyl LPs. Those things weigh a ton.