Light as a feather but strongest man cannot hold

Answer for the previous riddle: It reads the same upside down
The next question is in the video below.

You can get the answer if you click the link inside the video.

Next riddle: What is light as a feather, but even the strongest man cannot hold it more than a few minutes?
 
My videos can be found on YouTube. The riddles are inside my videos. I upload videos with this username: IhaveBIGplan
Play free online games or make money from your flash games - link
Site created with: link | link 2