When creating content for euclid in various modeling programs please remember that:
1 unit = 1 meter. So approximately an object with 0.05 width is a pebble and an object with 10 width is a light truck.
This will make sure all objects stay in sync with their physical representation.
For exporters to the ogre3d mesh format please see:
http://www.ogre3d.org/wiki/index.php/Exporters
For tools to aid you in the process of creating content please see:
http://www.ogre3d.org/wiki/index.php/OGRE_DCC_Tools
The price of freedom is eternal vigilance.