BackTracker V2.0 is a security godsend for some, but for others its just about the a sure way of breaking someones WEP encryption. (it is illegal to eavesdrop and or to use the internet in most place). so if you don't hace a AirPcap compatible wireless adapter, do not worry BackTracker is to the rescue. pack with unlinited amount of tools and features it is truly great. and to topp it all it is also available as a Live CD, meaning you do not need to install it, you can just runn of the book CD or Memory stick (saves you an 8p CD lool)
it is extreemly fast ad breaking wep especially 64bit. and the limits are the sky, with the right gear youcan probably log you neighboors keyboard strocks.