Originally Posted by godisawesome
I've only a few rules when it comes to competent use of kryptonite:
1) Extremely rare. As in, you can't find it on Earth at all. And the one piece you get is relatively small, say 2-3 pounds. You could even have a whole subplot of a movie dealing with denizens of Earth becoming aware that kryptonite even exists and having a MacGuffin chase for the thing, with multiple characters being killed to obtain it.
2) Does a lot more than kill Superman. Post-Crisis they depicted kryptonite as being an alien fuel source left over from a kryptonian superweapon's effect on krypton's core. I say you make it clear that it can actually fuel things like Metallo and is highly responsive. I also like the idea that it can poison and kill humans over time, making it more of a nightmarish super-radioactive element.
3) Does not appear in the first movie. Superman and Zod should be enough of a smackdown for us to avoid insta-kill glowing green rocks.
I say you attach it to Brainiac's ship in the second movie and have him be the excuse for it's transport.
A lot of good points here.