THE PROBLEM WITH GPS WATCHES FOR RUNNERS. “It seems clear enough that a GPS watch is not very accurate, yet online runners’ forums, like one at the Web site of Runners World, are filled with comments from confused athletes who rely on the devices.”

They’re also kind of pricey, at least to me, though that’s gotten better. My take: First, people sure expect a lot from devices that are basically kind of miraculous. Second, if I were to start running again, I’d get one of these anyway because the motivation-value would outweigh any problems with accuracy. Then again, the athletes described here are a lot more serious.