A 5-second intro :
Installing Node on Ubuntu :
As Node is quickly evolving I would recommend that you build Node directly from the source code. Otherwise, simply execute $ sudo apt-get install nodejs at the prompt.
[Note that at the time of this post the latest source will build v0.6.9 where as Ubuntu 10.10 will install 0.1.97]
First, install the required packages to build the latest version of Node
$ sudo apt-get install g++ curl libssl-dev apache2-utils
Second, download the latest source tar.gz from here and extract (or you can pull a copy from github).
Finally, 'cd' to the directory and execute the following commands at the prompt.
$ sudo make install
That's it! Now try out your new Node installation with a typical 'Hello World' example.