so far, the only 3D 'engines' i've found to have a high degree of cross platformability between the two are Torque (the scripts can just be copied over and run, same with the content), C4 (not really much experience with it), and BlitzMax (the demo releases only)...
Do you know unity ( http://www.otee.dk/ )? Watch out for 1.5 coming soon! :O)