Hi Michael T - well you could send whoever you want to view your model a link to the MoI "no save" trial version which they could then install and use to open up your main 3DM file.

The direct link to that one is here:
http://moi3d.com/2.0/trial/moi_v2_nosave_trial_setup.exe


There's a freeware viewer and converter program here that loads IGES or STEP files:
http://iges2step.narod.ru/

You can probably find a few other OBJ viewers by google search, like:

http://www.aweapp.com/obj_viewer/
http://pti.iu.edu/avl/GLM_AVL


Or probably the trial versions of various different programs might work, like you could use the trial version of Silo (http://www.nevercenter.com/silo/) for an OBJ viewer.


- Michael