Hey all,
I wanted to announce a new package that resulted from my work this
past summer. It's a handful of tools I've found useful for building
urdf models. It's a stack with the clever name, "urdf_tools".
http://www.ros.org/wiki/urdf_tools
https://wu-ros-pkg.svn.sourceforge.net/svnroot/wu-ros-pkg/stacks/urdf_tools/trunk/

There are four packages inside.
 * easy_state_publisher - Similar to robot_state_publisher, but
doesn't require any input. Just outputs zeroed joint states or
transforms for any given urdf model.
 * joint_controller - Publishes joint states using a GUI interface
 * arm_kinematics - My attempt at a generic kinematics package not
coupled to the PR2 hardware
 * simmechanics_to_urdf - The biggest package of all of them, used for
converting CAD-like models to URDF.

More information is on the respective wiki pages. Questions feedback
and bug reports are most welcome.
-David Lu!!