I think you push it in... It almost looks like a huge curtain hook.. and then reposition it once you have pierced the drywall... a long section goes into the wall and braces against the drywall above where hole is made and allows for a heavy load to be supported. The hook supposedly is easy to remove and leaves but a small hole that you could patch with toothpaste (apartment trick!).. or for real..spackling..
I did see the segment the other week when they used those... Somehow when he was trying to pierce the drywall it didn't look as easy as they make it look on the commercial!
Here is a link... I guess the hook looks like a huge fishing hook..
Hopefully from the picture, you get the general idea.
http://www.herculeshook.net/
I'm really tempted to order them.. Even just to hang pictures and such.. Would be nice to not have to use those stupid plastic anchors!