Cinnamon in Ubuntu 11.10

How To Install Cinnamon
The .deb files are available on the Github, which you can install by downloading and double clicking. But if you want to keep Cinnamon updated I recommend adding its PPA to your system. To add the PPA, open the terminal and run this command:
sudo add-apt-repository ppa:merlwiz79/cinnamon-ppa

Then run this command
sudo apt-get update && sudo apt-get install cinnamon-session cinnamon

Once installed, logout and from the login screen select Cinnamon. You will be greeted by the brand new Cinnamon desktop. I found the global menu on the desktop so I went ahead and removed app-menu.

Read more about it here.