The more difficult question is how to install node as an unprivileged user? Here's how

wget http://nodejs.org/dist/node-v0.2.2.tar.gz && tar xzf node-v0.2.2.tar.gz && cd node-v0.2.2 && export PREFIX=~/opt && ./configure && make && make install && echo 'export PATH=~/opt/bin:${PATH}' >> ~/.bashrc;

Otherwise any npm package will be able to rm -r you.