Doting pet owners can now track their beloveds with Tagg, a GPS-enabled wireless pet tracker that easily fits onto any collar. Log into your online account for your pet's current location and a feed of the activity they've had in the past 24 hours. You have the option of being alerted about changes in your pet's activity. The system costs $99.95 for the devices, along with a service fee of $7.95 per month. Each additional tracker is $0.50 per month.