Apple's new iOS 8 is great, and one of those great new features is Continuity. With Continuity, users of multiple Apple products can take a phone call on one device and switch to another on the fly. I typically leave my iPhone docked at the entrance to my house and then I work upstairs on my MacBook. When the phone rings, I have to make a mad dash to answer it. Now I can take the call on my iPad. And soon, with Mac OS X Yosemite, I can answer the phone call on my MacBook!
But not everybody wants every device to ring when a call comes in. It can get awfully annoying in a household full of Apple gear. Fortunately, there's an easy solution. On any iOS device you don't want to answer calls on, go to Settings>FaceTime and turn off iPhone Cellular Calls. That's it! Now, incoming calls will only go through on the devices you want them to.