I'm watching BAW155 en-route to Cairo at the moment, using RadarBox, Live Flight Tracker and the free web based AirNav Flight Tracker. Here are some screen shots to show the 3 in use. Different information displayed on each screen, but the free Flight Tracker is excellent if you only want to follow one aircraft. Links to the full size pictures are under the thumbnails.
(http://farm4.static.flickr.com/3006/2616589790_704456858a.jpg)
http://farm4.static.flickr.com/3006/2616589790_0d486c8786_o.jpg
(http://farm4.static.flickr.com/3155/2616590048_26be0e3bdc.jpg)
http://farm4.static.flickr.com/3155/2616590048_1b2f5958a3_o.jpg
(http://farm4.static.flickr.com/3062/2616590428_1e8fd8cbdb.jpg)
http://farm4.static.flickr.com/3062/2616590428_9a7233c97b_o.jpg