How to Install GNOME Shell in Ubuntu Linux
Installing GNOME Shell in Ubuntu 9.10 (Karmic Koala) is easy. This is how you do it.
$ sudo apt-get install gnome-shell
Once GNOME Shell is installed, you can start it by running the following command :
$ gnome-shell --replace
Remember that GNOME Shell in your repositories is a preview version and is not the final product.
If you get a black screen (as I did) , then you should set the value of the
GNOME_SHELL_DISABLE_TFP variable to 1 prior to starting GNOME Shell.
$ export GNOME_SHELL_DISABLE_TFP=1