Backtrack is one of the most top rated Live Linux Distributions (meaning you can run straight from the CD). Backtrack is focused on penetration testing, and comes pre-packed with many applications to analyse and test your LAN, Wifi, Bluetooth... the list continues.
I have often had a play around with Backtrack, and find the tools and applications very useful. However, with the free storage space on my laptop is becoming ever more limited, and I have no room to install it under a Virtual Machine. The below instructions will show you how you can install all of the Backtrack applications on your current Ubuntu installation.
Add the following line to your /etc/apt/sources.list
deb http://repo.offensive-security.com/dist/bt4 binary/
Now to import the Backtrack GPG key and to update the sources:
wget http://repo.offensive-security.com/dist/bt4/binary/public-key && sudo apt-key add public-key && sudo apt-get update
Fantastic! Now we have all the new Backtrack applications ready to install. You can find these applications in your Synaptic Package Manager, under the sections BackTrack - Web (for example). If you are wanting to install all of the new applications quickly, you can run the following command:
links -dump http://repo.offensive-security.com/dist/bt4/binary/ | awk '{print $3}' | grep -i deb | cut -d . -f 1 > backtrack.txt
This command will use the links text browser to grab a complete list of packages and store them into the file backtrack.txt. Each application will then be installed one by one. Be warned! There are 182 applications listed within the text file that you make. This may take some time downloading, all depending on how fast your internet connection is.