They're for clearing the road,spare bikes/parts/mechanics/food and team directors, who give strategy to the riders...
Contador is likely to get it now unless he cracks in the mountains somewhere(which happens) but it sure would be something if Lance got another one...possible, if he has a killer time trial and chips away at Contador in the mountains...
One day I gotta go to France and see it in person...that would be cool!
Tony