Answer:
What is weightless but it needs two person to hold it?
I'm not man's best friend, I'm their enemy, I can mark your end, yet you do not see me, I am very small, but very tough, If you have me, then you have it rough.
I bind it and it walks. I loose it and it stops.
I can be cracked, I can be made. I can be told, I can be played.
I run through hills. I veer around mountains. I leap over rivers. And crawl through the forests. Step out your door to find me.
What did the piece of wood say when he saw the screwdriver and screws approaching?