Blender To Iris
*You need the export script OgreXMLConverter to make item.mesh.xml
*You need also the Command-line Tools to convert item.mesh.xml to item.mesh
http://www.ogre3d.org/index.php?option=com_content&task=view&id=413&Itemid=133
Before export your item go in editing mode, select your item and press "w" and "flip normal" to a good ingame visual.
After place your item in custom directory.
Orientation of your mesh
For a good orientation of your item the best way is to place the point of origin of your item same as the origin of your blender grid.
*left clic near the origin blender grid
*repeat this with all cam view (1 3 and 7 keys)
*Shift+S and Cursor>Grid. Now your cursor is exactly at the center of the grid in all axes
*go in Object mode (press "tab" if you was in editing mode)
*clic center cursor in mesh menu. The origin of your item is now at the origin of the grid.