Use This Terminal Command to Force Eject a Stubborn Disk From Your Mac
by Jake Peterson from Lifehacker on (#626W3)

We've all been there: You have an external hard drive or USB thumb stick plugged into your Mac, and you're ready to part ways. You drag it to the the Trash, or right-click to eject it, only to be greeted by the infamous, The disk wasn't ejected because one or more programs may be using it." You look around your Mac:...