I came across a website that shows in real time where all the TDF riders are located (on a map), speed, and a whole bunch of other interesting data. The website is Home - Tour de France 2015 with a beta live tracking map at Beta Live Tracking.

You can read about the TDF GPS Transponders which produce this live data at: Big data comes to the Tour de France - BikeRadar

I did a search on the forum and didn't find any reference to this tracking website, so I thought I'd post. My apologies if this has already been posted elsewhere.

Cheers.