Update 7/31/2014: The good news is I can confirm this method still works on a fresh Linux Mint 17 “Qiana” install. However, you need to install the following dependencies first:
$ sudo apt-get install build-essential openssl libssl-dev pkg-config
OMG, this could be the first time I’ve ever been able to post a link to a how-to without a list of comments and addendums:
These instructions worked perfectly to install NodeJS and NPM on Ubuntu as a non-root user. Huge props to Tom Novelli. Respect.