I can't stay away from Node.js. It's just too much fun. So the first thing I did tonight upon finally settling on Linux Mint/Cinnamon on my laptop was install RVM and Ruby. But then I installed Node.js!
Getting a recent version of Node.js installed on Ubuntu or Ubuntu-derivatives is no walk in the park. The version in the official repositories is out of date. So you've got to add an unofficial (and untrusted) source or compile it yourself.
It turns out there is another, much easier way. Some nice chap has posted a script that will set-up a Rock Solid Node.js Platform on Ubuntu. As an added bonus, you can configure the script to install Mongo and/or Redis too.