Answer:
A mile from end to end, yet as close to as a friend. A precious commodity, freely given. Seen on the dead and on the living. Found on the rich, poor, short and tall, but shared among children most of all.
To cross the water I'm the way, for water I'm above. I touch it not and, truth to say, I neither swim nor move.
What zips through the sky with a tail of fire and dust. It could be an omen, its origin to discuss?
I count time, but have no end. Tick tick, but I am not a clock. What am I?
Just head and foot yet never tires of dancing.
You use it between your head and your toes, the more it works the thinner it grows.