I know Superman grew up in Kansas, but now we have indirect scientific evidence of it.
Last year, a man found the largest sample of a Pallasite meteorite ever (1400 pounds!) in Kiowa county, Kansas. Pallasites are not much to look at from the outside: generally rusty orange and brown lumps. But slice them open, and they are the gems of the meteorite world. They're woven through with iron in a web-like structure, and lodged in the interstices are crystals of olivine, greenish yellow and phenomenally beautiful when help up to the light.
As it so happens, kryptonite is a pallasite. Coincidence?
Well, now it's come to my attention that the one meteorite found in Kansas isn't alone: there appears to be a strewn field of meteorites in Kansas. And they're all pallasites. Don Stimpson and Paul Ross, who found the meteorites, should be pretty happy since pallasites sell for quite a bit of money. Even small ones are commonly $5-10 per gram.
I have no idea how much Lex Luthor would pay for them. Given his history, probably nothing. But I'd keep them under constant guard.
Update: One of my favorite blogs, Thoughts from Kansas, has more info. Looks like there is a brewing storm over meteorites in Kansas.
Tip o' the Whipple Shield to P Z Myers at Pharyngula, who really should have emailed me this link.