I know about Trip.com's flight tracker...a really neat applet on the web. I was wondering whether there is any legal reason why, in addition to the data you get, you couldn't also get the aircraft registration number. Seems to me that if you can get the plane's present heading/altitude/speed, the registration number should be no big deal. I'd love to track flights & see whether I've been on a particular aircraft. My log now numbers 275 commercial flights, every one with a registration number.