The latest version of the install script is always available at
https://bitbucket.org/code_iai/iai_environmental_setup
Just download the contents or use
$ git clone https://bitbucket.org/code_iai/iai_environmental_setup.git
to clone the repository.
Among other things the script will install ROS Fuerte on Ubuntu Oneiric (11.10). To change to a newer version of Ubuntu adapt line 15 to your needs (i.e. adapt /ubuntu <yourVersion> main). To run the script just go to the download directory and do
$ ./installros.sh
the script will then ask for your sudo password.
Thats it, just wait for it to finish and everything should be up and running.
To add an additional debian package to the install routine you just have to edit the 'packages' file inside the download directory and add the required package name. Make sure you leave exactly one empty line at the end of the file.
Same goes for additional ROS package repositories that you want to be cloned by the script. Just add them to the '.rosinstall' file. If you want those packages to be 'rosmaked' by the script, also add them to the 'makepackages' file. Make sure you leave exactly one empty line at the end of the file.
Note: If you add any repositories that require a password the script will stop and wait for you to enter it at one point.
If you want to use a specific version of CRAM, then there is a shell scripts that helps you to checkout this version. Please see the following links to determine the right version and how to install it.