[ros-users] Help installing third party stacks/packages

I want to do the urdf tutorials here: http://www.ros.org/wiki/urdf/Tutorials

The later ones require urdf_tutorial which is in urdf_tools, which is hosted
at wu-ros-pkg <http://www.ros.org/wiki/wu-ros-pkg>

What I can't seem to find out is how to install this with rosinstall.
Clearly I'm missing something trivial, but what?

I'm running on Ubuntu 10.10, and I installed with apt-get, but I'd like to
know how to do this on OS X too since I'm planning on doing most of my ROS
development there.

cheers,
Tom