Following these directions to install nodeJs and socketIO on a Raspberry Pi

    http://www.bartbania.com/index.php/build-your-own-google-tv-using-raspberrypi/


When I try running 

    npm install

get the following error

    Please try running this command again as root/Administrator.

Prefixing with 'sudo' simply gives a 'command not found'

Anyone know how to resolve this?

I tried to recursively change the owner of the files in my /usr/local folder to the current user:

    sudo chown -R $USER /usr/local

But it makes no difference