Check this out!!
Apparently NORAD has a special Santa Detection System where they track Santa and his reindeers' progress across the world using several hi-tech methods, such as "radar, satellites, and figher jets".
Click on this link to follow his progress across the globe on msnbc.com.
And click on this link to access NORAD's special Santa Tracker page. Be sure to check out the "How We Do This" section!