This would make a great hack for tracking

Community General Discussions
1

this could be a great tracking device if it was hacked and added to a robot. would be great to know how to install the technology it uses into a robot

 

http://www.maplin.co.uk/Module.aspx?ModuleNo=99293

tracker.jpg

2

Might look at active RFID
Might look at active RFID devices, and directional antennas, from what I could find about the device.