I’ve just come across a wonderful site called ‘Heathrow Cam‘
The site uses a ADS-B receiver and a fixed, motion sensitive camera to capture an image and details of incoming flights. (ADS-B is not ‘radar’ but it’s a transponder radio which received information broadcast by commercial airlines relating to thier position in space)
Live Radar Image
Also very exciting is their live radar image which shows all London area traffic in radar-like display. This wonderful radar like resource updates every minute showing aircraft id, type, altitude, speed, departure and destination airport codes. Great fun to use.
Check out these other airplane tracking tools.