[PlayerStage-Gazebo] howto create immovable objects

[Solly B. <so...@cs...>]

Can anyone give me some advice on creating immovable objects in Gazebo? 
eg. a box on the ground which doesn't move when things bump into it.

In ODE this is done by creating a geom without a corresponding body, but 
I'm having trouble translating this into the gazebo API without causing 
it to crash.

Any hints would be appreciated... =-)

Thanks, Solly