Updating rubygems on Ubuntu

If you have ever tried to update rubygems on a base Ubuntu 10.04 or 10.10 install you will have been greeted with:

# gem update --system
        ERROR:  While executing gem ... (RuntimeError)
            gem update --system is disabled on Debian. RubyGems can be updated using the official Debian repositories by aptitude or apt-get.

You can work around this limitation:

# gem install rubygems-update
# /var/lib/gems/1.8/bin/update_rubygems

You will now be able to update rubygems using the standard set of commands.