Been staring at the back of your iMac, wishing you could take advantage of all that space? Behold Twelve South‘s BackPack. It’s a small stainless steel shelf that attaches to the back of the iMac desk stand using two clips, it won’t scratch because gravity holds it in place. Park a hard drive, USB hub or your favorite Star Wars figure on it. Because it’s height-adjustable, you can add more than one. And its perforated bottom also allows you to use it for cable management. $29.99 and currently free shipping.