Yeah, I have been riding with two friends: one who does alot of road biking, and the other who has superhuman cardio capacity, kinda like Lance.
The road guy advised me to downshift anytime I cant see what is ahead of me, that way I will be in a low enough gear to tackle an uphill, and if it ends up being a downhill or straight away, I can always shift up.
Seems to make sense… I think