Apple filed a patent application on January 7, 2011 that was today published for public viewing. The patent application is for a "Mounted Shock Sensor." Just what would this shock sensor do? If built into a piece of electronics, it sounds as if it could actually void your warranty.
Here's the deal: Its a small shock sensor. If it receives enough of a jolt to knock things out of line, the technician will be able to see that. It doesn't seem to say it explicitly here, but being that Apple usually doesn't problems that come from user neglect or abuse, this would probably be the point where the technician says, "Nope. This person dropped their iPad too hard. They will have to pay for repairs."
Here is the description information from the patent application:
"This application is directed to a shock sensor mounted in an electronic device. The shock sensor includes both active and passive shock detection methods that allow a technician to determine whether the electronic device was subjected to a shock event that exceeded an impact threshold level. The shock sensor may include shock detection contacts that form an electrical circuit that remains open in the absence of a shock event that exceeds an impact threshold level. In response to a significant shock event, a movable component or substance of the shock sensor may move from a first position to a second position, thereby closing the electrical circuit formed by the shock detection contacts. The change in circuit may be detected and used to provide active indication of whether the electronic device has been subjected to a substantial shock event. In addition, the shock sensor may be observed to passively determine whether the electronic device has been subjected to a substantial shock event."
We hope that something like this could be used to run diagnostics rather than our guess of it just meaning that they will chalk it up to the user not taking care of their device.