X-Ray Folders on OS X

This is a feature I came across very recently, on Lifehacker ! You can actually make folders display content on Quick Look in 'X-Ray' fashion ! Here's get those X-Ray folders:

1. Open Terminal
2. Copy and paste this command into the Terminal window
defaults write com.apple.finder QLEnableXRayFolders 1

3. Log out and log in or type one more command if you don't feel like logging out:  
killall Finder

4. See the magic happen, when you Quick Look a folder with documents or pictures

After you do all that successfully, here's what Quick Look will look like:

To revert back to the default Quick Look view, copy and paste this into a Terminal window

defaults write com.apple.finder QLEnableXRayFolders 0