Tethered shooting can mean a couple of different things, but usually it would involve sending the images back to a remote display system. From that remote display you can see a live picture as though it was an extension of the camera's viewfinder and then when you shoot it also has the capability of storing the shot in that remote device. This would require much more bandwidth and technology.
Some people use it (perhaps not quite correctly) when referring only to remote triggering.
The remote trigger you pointed us to is about as basic as they get. I found a more sophisticated remote switch for your camera which allows you to set a timer for delayed shots or intervals for timelapse photography. Theoretically, it would be possible to duplicate this sort of behaviour from a laptop or other device, but this is still far simpler than the technology that you would need to stream images back to the device from the camera, which probably explains why you are having difficulty finding anything if you are searching for any sort of "tethering".
One possible solution for your camera, if you really are concerned about seeing the image remotely, would be a combination of one of those remote triggers with an Eye-Fi SD card in your camera to allow you to stream your images back to another wifi enabled computer or device.