Ruby: Installing rmagick on Ubuntu

I'm trying to get RMagick setup on Ubuntu 10.04. Looked [here][1] but had no joy. I even compiled and installed ImageMagick from source, but the instructions [here][2] still didn't help me when I try to install RMagick using RubyGems. I got this error: carcher@carcher-laptop:~/Code/temp/RMagick-2.13.1$ sudo gem install rmagick Building native extensions. This could take a while... ERROR: Error installing rmagick: ERROR: Failed to build gem native extension. /usr/bin/ruby1.8 extconf.rb extconf.rb:1:in `require': no such file to load -- mkmf (LoadError) from extconf.rb:1 Gem files will remain installed in /usr/lib/ruby/gems/1.8/gems/rmagick-2.13.1 for inspection. Results logged to /usr/lib/ruby/gems/1.8/gems/rmagick-2.13.1/ext/RMagick/gem_make.out carcher@carcher-laptop:~/Code/temp/RMagick-2.13.1$ What does it all mean? :) I'm new to Ruby and RubyGems so please be gentle. My setup is as follows: Ruby: 1.8.7 RubyGems: 1.3.7 I'm pretty much out of ideas (and tired too!). I tired to compile RMagick from source using the link above but it failed as there was no `./configure` script :( Any and all help appreciated! [1]: https://stackoverflow.com/questions/1482823/is-there-an-easy-way-to-install-rmagick [2]: http://rmagick.rubyforge.org/install-linux.html