Answer:
What travels from coast to coast without ever moving?
Once you know it exists, it no longer exists. What is it?
Angels and pilots earn these.
It is a form of plastic money.
You fill it and it empties, A metaphor for plenty, Depending on what half you see, It's either full or empty
What sphinxes employ and players enjoy.
Easy
Animal
Difficult
Food
Funny
Kids
Logic
What am I?