I don't know about your kid, but K2 does not have an iPhone. So that means I'd have to load CodeGoo's Baby Monitor onto my iPhone, and then program it to call me on my other phone when it detects some baby noise. And then I'd leave it in the crib with her, because it also calls me when K2 picks it up, just in case she wakes up in silent mode. And I'd have to be sure to set call forwarding, so that people calling me on my iPhone don't inadvertently wake up the sleeping kid.
Only problem: I don't have an iPhone, either.
um, released two weeks ago: Baby Monitor by CodeGoo, $0.99 "for the first week only" [codegoo via geekdad]