The technology lets users track a letter's every move. A vibration- and tilt-sensitive motion detector determines whether the Logger was sitting idle, being sorted, or bumping along in a truck. This data syncs with the GPS locations via Google Earth, allowing officials to spot places where mail lingered too long. The USPS is still weighing the results from last year's trial run of the technology (in the Denver area), and there are no plans yet for a commercial model. But even if you won't be able to personally track your Valentine's cards, it could help ensure that those Luddite love notes arrive on time.