GUI for WEP/WPA crack (Looks very simple to use - still testing it but so far very impressed)
Fern is built into Backtrack R3 but for those using older version, like me R1 still and happy!
root@bt:~# apt-get install fern-wifi-cracker
2. To start
root@bt:/pentest/wireless/fern-wifi-cracker# python execute.py
or via the gui
BackTrack / Exploitaion / Wireless Exploition Tools / WLAN Exploitation Tools / fern-wifi-cracker
3. Select Interface / pull down use wlan0
4. Scan for Access points
5. Click on Wifi WEP
6. Choose the AP of choice and Click Attack
myexploit 
thanksssssssssssssssss