Well, today it is time for WPA Encryption.
Click on the image to see video.

How many times when you were walking with your notebook you have seen available wireless networks with WEP encryption, I am sure you have. This video shows how you can decrypt 64 bits WEP key in just 10 minutes. Although video uses Whoppix distro, still you can do it if you get Backtrack distro that is a Linux distribution oriented to Security Auditing and Pen-Testing.
Click on the image to see video.