Ubuntu 11.10 comes with the Unity (with 3D effects) as the default session and a fall back Unity 2D for those having graphic cards without support for 3D. Most of us who have already used Classic Gnome Desktop will want this in Ubuntu 11.10 as it consumes less resources and faster when compared to the Unity default session.
This howto shows in simple steps to get the Classic Gnome Desktop and Shell in Ubuntu 11.10:
1. Open the Terminal
Press ALT+F2 to get the Run dialogue window. Then type terminal and press enter
2. Install the Gnome fallback session
Type the following commands to install Gnome Session Fallback:
sudo apt-get install gnome-session-fallback
Thats it. Enjoy the classic Gnome Desktop...!