Chris Forsberg created an example Internet of Things project to track luggage using ThingSpeak, an Adafruit GSM Module, and an Arduino. He built a simple system to send data to ThingSpeak, such as latitude, longitude, and status data. ThingSpeak exposes a data channel API for any system like this to being able to store data and then process the data.
The idea is that it is frustrating waiting for luggage at the airport and wondering where it is and why it is not on the baggage carousel. With this project, you can track luggage from start to finish. The advantages are not only for the traveler, the airlines could track luggage as well and get quality statistics for each airport. And, the base system has many applications outside of travel such as the Automotive Industry.
Chris explains the project really well on his blog and with a YouTube video.