I agree with Kathryn and would go with Joel for a boy and Laura for a girl, in honour of Clark's parents. However, the secret identity will be shot if anyone ever says "Joel and Laura" in the same breath -- unless the names of Superman's parents aren't common knowledge?

"Some prices are just too high, no matter how much you may want the prize. The one thing you can't trade for your heart's desire is your heart."
--Lois McMaster Bujold, "Memory", 1996