Like teenagers, pets are prone to rebellious behavior, often sneaking out in the middle of the night or driving without a learner's permit. Keep better track of your runaways with today's Groupon: for $27, you get a microchip for your pet from the doctors at Montgomery Animal Hospital in Rockville (a $54 value).

Montgomery Animal Hospital's veterinarian, Dr. Jaffe, permanently links pets to their owners with a simple microchip-insertion procedure. Widely used by shelters and humane societies, the system swiftly locates runaway pets that have fled homes in search of buried bones or casting calls. During each application, Dr. Jaffe quickly and painlessly implants a grain-size microchip between the shoulder blades of a cat or a dog. The implant lasts a lifetime and, similar to a routine vaccination, requires no anesthetic.