I get the impression that some of you don't approve of cable runs?
I have a big yard with no fence, Earnest used a cable run for his first year or so, until I acquired enought chain link panels to set up a play yard for him. I've used them before, too- they are certainly safer than staking a dog out, or tying them to a stationary object. I like to run mine from above the back door, so the dog can come to the door if it wants to come in.
Of course, I would never leave a dog on one unsupervised until they got the hang of it, and NEVER when I wasn't home or for an extended period of time. But to go out and potty, or spend some time out from under mom's feet, to enjoy the sunshine and fresh air, they are a good alternative for those of us who rent and can't afford or aren't allowed to fence.