> I thik you missed the point. I don't have to ask Nintendo. I used to run a Video
> Rental Store and, just like Blockbuster, I didn't need Nintendo's, Sony's, or
> Sega's permission.
As long as you are shipping the cartridges out and getting them returned afterwards then you are fine. If you are distributing them in any form other than you originally bought them then you are breaking copyright.
Renting is generally prohibited in the terms and conditions on the retail media of games and movies. Blockbuster don't buy retail. Whether they can legally enforce this is down to local laws, however it's obviously a moral problem.
For christians out to make some honest dough, you seem to be misguided.