The official site is at http://www.letour.com but it's remiss of Le Tour organisers not to have registered the obvious URLs that could be used by underhand operators such as the ones who redirect tourdefrance.com to NoCreditCard-Peepshow Live.
The site is registered to M. Garcia of Apartado de correos 5, Playa del Ingles Gran Canaria in Spain.
Believe me, tourdefrance.com is not suitable for family viewing!
It's even worse than whitehouse.com, which is probably the world's most infamous website squat.
(Thanks to an academic informant for letting us know his search for a Tour de France website was an initially shocking one).