I came across a very interesting Web site via a link at Dark Roasted Blend. It's called "Stolen Camera Finder".
It works like this:
Every photo you take with your digital camera contains hidden information about both the image and the camera such as the make, model and date. This information, called exif data, can also include a unique serial number which identifies your camera.
stolencamerafinder crawls the internet searching for photos, collecting the serial numbers of the cameras that took them.
When you use the drag & drop feature, stolencamerafinder reads the unique serial number from the exif data of your photo and uses it to match against serial numbers it has stored.
I guess this won't be worth the trouble to use for a low-cost point-and-shoot camera, apart from the curiosity factor; but if you're someone like Oleg Volk, with many thousands of dollars invested in cameras and other photographic tools, it might be helpful in recovering very valuable equipment.